/**
@page changes Changes


## 0.6.9 January 30 2017

- Added chart trendlines. See @ref chart_trendlines and
  @ref chart_data_tools.c.


## 0.6.8 January 28 2017

- Added chart error bars. See @ref chart_error_bars and
  @ref chart_data_tools.c.

## 0.6.7 January 24 2017

- Added chart data labels. See @ref chart_labels.


## 0.6.6 January 22 2017

- Added functions to set chart Up-Down bars: see `chart_set_up_down_bars()`
  and `chart_set_up_down_bars_format()` and @ref chart_data_tools.c.

- Added functions to handle blank and hidden data in charts: see
  `chart_show_blanks_as()` and `chart_show_hidden_data()`.


## 0.6.5 January 21 2017

- Added functions to set the overlap and gap between series: see
  `chart_set_series_overlap()` and `chart_set_series_gap()`.


## 0.6.4 January 20 2017

- Added chart data table option, see `chart_set_table()` and
  `chart_set_table_grid()`.

- Added Clustered Chart example, see @ref chart_clustered.c.


## 0.6.3 January 19 2017

- Added `chart_set_drop_lines()` and `chart_set_high_low_lines()` functions to
  add chart Drop and High-Low lines to indicate category values.
  See @ref chart_data_tools.c.


## 0.6.2 January 17 2017

- Added `chart_series_set_smooth()` function to set the line smoothing
  property of a line or scatter chart series.


## 0.6.1 January 16 2017

- Added option to set formatting for points in a chart. This allow the colors
  of Pie chart segments to be defined. See @ref chart_points.


## 0.6.0 January 15 2017

- Added option to set the number format for a chart axis, see
  `chart_axis_set_num_format()`.

- Added "invert if negative" option for series fills, see
  `chart_series_set_invert_if_negative()`.


## 0.5.9 January 14 2017

- Added support for chart axis crossing. See `chart_axis_set_crossing()` and
  `chart_axis_set_crossing_max()`.


## 0.5.8 January 13 2017

- Added `chart_axis_set_major_tick_mark()` and
  `chart_axis_set_minor_tick_mark()` functions to chart axis tick marks.


## 0.5.7 January 12 2017

- Added `chart_axis_set_display_units()` function to set chart axis display
  units.


## 0.5.6 January 11 2017

- Added `chart_axis_set_interval_unit()` and `chart_axis_set_interval_tick()`
  functions to adjust category axis intervals.


## 0.5.5 January 10 2017

- Added `chart_axis_set_major_unit()` and `chart_axis_set_minor_unit()` to set
  the major and minor units of a category axis.


## 0.5.4 January 9 2017

- Added `chart_axis_set_label_position()` option to position the axis labels
  (numbers).

- Improved documentation for @ref ww_charts_axes.


## 0.5.3 January 8 2017

- Added `chart_axis_set_position()` option to position a category axis
  horizontally on, or between, the axis tick marks.


## 0.5.2 January 7 2017

- Added option to turn off chart axis: `chart_axis_off()`.


## 0.5.1 January 6 2017

- Added chart major and minor gridlines handling, see:

  - `chart_axis_major_gridlines_set_visible()`
  - `chart_axis_minor_gridlines_set_visible()`
  - `chart_axis_major_gridlines_set_line()`
  - `chart_axis_minor_gridlines_set_line()`


## 0.5.0 January 5 2017

- Added chart and plot area formatting. See `chart_chartarea_set_line()` and
  `chart_plotarea_set_line()`.


## 0.4.9 January 4 2017

- Added support for chart patterns. See @ref chart_patterns.


## 0.4.8 January 3 2017

- Added support for chart markers. See @ref chart_markers.


## 0.4.7 January 2 2017

- Added `chart_axis_set_reverse()` function to reverse the order of a chart
  axis.

- Added `chart_axis_set_min()`and `chart_axis_set_max()` functions to set the
  minimum and maximum value for a chart axis.

- Added `chart_axis_set_log_base()` function to set the log base of a chart
  axis.
  Feature request [#70][gh_70].

  [gh_70]: https://github.com/jmcnamara/libxlsxwriter/issues/70


## 0.4.6 January 1 2017

- Added functions to set chart line and fill properties, see:

  - `chart_series_set_line()`. Feature request [#83][gh_83].
  - `chart_series_set_fill()`.
  - `chart_axis_set_line()`.
  - `chart_axis_set_fill()`.
  - @ref chart_lines.
  - @ref chart_fills.

  [gh_83]: https://github.com/jmcnamara/libxlsxwriter/issues/83


## 0.4.5 December 31 2016

- Added functions to set chart legend properties: see  `chart_legend_set_position()`,
  `chart_legend_set_font()` and `chart_legend_delete_series()`.


## 0.4.4 December 30 2016
- Added chart fonts. See `chart_axis_set_name_font()`, `chart_axis_set_num_font()`,
  `chart_title_set_name_font()` and @ref chart_fonts.


## 0.4.3 December 26 2016

- Added `workbook_get_worksheet_by_name()` function to get a worksheet
  object from its name.

- Added `workbook_validate_worksheet_name()` function to validate a worksheet
  name.

- Fix for parameter length check when strings are UTF-8.
  Issue [#84][gh_84].

  [gh_84]: https://github.com/jmcnamara/libxlsxwriter/issues/84


## 0.4.2 July 14 2016

- Added support for OpenBSD and better support for FreeBSD. See @ref gsg_bsd.


## 0.4.1 July 11 2016

- Switched to using
  [tmpfileplus](http://www.di-mgt.com.au/c_function_to_create_temp_file.html)
  for temporary file handles to work around issue when the temp directory on
  Windows isn't writeable. The temp file directory is now also configurable at
  runtime, see @ref gsg_tmpdir.

  Issue [#63][gh_63].

  [gh_63]: https://github.com/jmcnamara/libxlsxwriter/issues/63


## 0.4.0 July 5 2016

- Added fixes for MSVC 2010.

- Refactored public APIs to return #lxw_error instead of int.


## 0.3.9 July 2 2016

- Added support for MinGW, MinGW-w64, Cygwin, MSYS and MSYS2.
  See @ref gsg_ming.


## 0.3.8 June 11 2016

- Added workbook functions to set custom document properties. See
  `workbook_set_custom_property_string()` and @ref doc_custom_properties.c.


## 0.3.7 June 2 2016

- Added updated Cocoapods file for Cocoapods 1.0.0. This also add support for
  the "use_frameworks" directive. Thanks to Ludovico Rossi. See @ref
  getting_started for instructions on how to use the cocoapod.

  Pull request [#50][gh_50].

  [gh_50]: https://github.com/jmcnamara/libxlsxwriter/issues/50


## 0.3.6 June 1 2016

- Fix for `worksheet_insert_image()` issue when handling images with zero dpi.


## 0.3.5 May 31 2016

- Refactored the error handling and reporting for when the file creation
  subsystem fails due to file permissions or other issues. The new error codes
  are in `#lxw_error` and the codes can be converted to strings, for reporting,
  using the new `lxw_strerror()` function.

  Issue [#49][gh_49].

  [gh_49]: https://github.com/jmcnamara/libxlsxwriter/issues/49


## 0.3.4 May 28 2016

- Updated the @ref getting_started docs with instructions on how to build
  libxlsxwriter for Windows using Microsoft Visual Studio and added links to
  the example MSVC project:
  [MSVCLibXlsxWriter](https://github.com/jmcnamara/MSVCLibXlsxWriter).


## 0.3.3 May 23 2016

- Added support for charts via the @ref chart.h "The Chart object". See the
  examples of the supported chart types:

  - @ref chart_area.c       "Area chart"
  - @ref chart_bar.c        "Bar chart"
  - @ref chart_column.c     "Column chart"
  - @ref chart_line.c       "Line chart"
  - @ref chart_scatter.c    "Scatter chart"
  - @ref chart_radar.c      "Radar chart"
  - @ref chart_pie.c        "Pie chart"
  - @ref chart_doughnut.c   "Doughnut chart"
  - @ref chart_styles.c     "Built-in charts styles"

  Feature request [#36][gh_36].

  [gh_36]: https://github.com/jmcnamara/libxlsxwriter/issues/36


## 0.3.2 April 8 2016

- Added the `worksheet_write_boolean()` function to write Excel boolean
  values.
  Feature request [#47][gh_47].

  [gh_47]: https://github.com/jmcnamara/libxlsxwriter/issues/47


## 0.3.1 January 9 2016

- Improved performance 20-30% for large data files.


## 0.3.0 January 4 2016

- Renamed `worksheet_set_row()` function to `worksheet_set_row_opt()` for
  consistency with current and future APIs. The `worksheet_set_row()` function
  is now used without the options parameter.

  Note: This is a backward incompatible change.


- Renamed `worksheet_set_column()` function to `worksheet_set_column_opt()`
  for consistency with current and future APIs. The `worksheet_set_column()`
  function is now used without the options parameter.

  Note: This is a backward incompatible change.


## 0.2.9 January 3 2016

- Added the `worksheet_insert_image()` function to add PNG and JPG images to
  worksheets. See @ref demo.c and @ref images.c.


## 0.2.8 December 22 2015

- Added `worksheet_set_default_row()` function to allow setting of default row
  height and hiding unused rows. See the @ref hide_row_col.c example.


## 0.2.7 December 21 2015

- Added support for escaping control characters in strings. This prevents
  unreadable files if string data contains control characters.
  Issue [#42][gh_42].

  [gh_42]: https://github.com/jmcnamara/libxlsxwriter/issues/42


## 0.2.6 December 19 2015

- Added `worksheet_protect()` function to protect Excel worksheet elements
  from modification. See the @ref worksheet_protection.c example.


## 0.2.5 December 14 2015

- Added `workbook_set_properties()` function to set Excel document properties
  such as Author and Title. See the @ref doc_properties.c example.


## 0.2.4 December 13 2015

- Added `worksheet_hide()` function to hide a worksheet. See the @ref
  hide_sheet.c example.

- Added `worksheet_set_first_sheet()` function to set the first visible
  worksheet in a workbook with a large number of worksheets.


## 0.2.3 December 12 2015

- Added `worksheet_set_tab_color()` function to set the worksheet tab
  color. See the @ref tab_colors.c example.


## 0.2.2 December 11 2015

- Replaced shared strings hash table with a Red/Black tree implementation for
  better performance.
  Thanks to Martin Renters. Pull Request [#41][gh_41].

  [gh_41]: https://github.com/jmcnamara/libxlsxwriter/issues/41


## 0.2.1 December 11 2015

- Added `worksheet_right_to_left()` function. This can be used to change the
  default direction of the worksheet from left-to-right when creating Arabic,
  Hebrew or other near or far eastern worksheets that use right-to-left as the
  default direction.

- Added `worksheet_hide_zero()` function to hide zero cell values.

- Added `worksheet_set_zoom()` method to set the worksheet zoom factor.


## 0.2.0 December 9 2015

- Added `worksheet_set_selection()` function to set the cell selected range on
  a worksheet.


## 0.1.9 December 7 2015

- Replaced main worksheet data structure with a Red/Black tree implementation
  for better performance when data isn't added in linear row-column order.
  Thanks to Martin Renters. Pull Request [#14][gh_14] and [#16][gh_16].

  [gh_14]: https://github.com/jmcnamara/libxlsxwriter/issues/14
  [gh_16]: https://github.com/jmcnamara/libxlsxwriter/issues/16


## 0.1.8 December 7 2015

- Added `worksheet_freeze_panes()` and `worksheet_split_panes()` to allow
  setting worksheet panes. See @ref panes.c example.

- Added link to [Xcode project][libxlsxwriterCocoaExamples] for iOS and OS X
  with Objective-C and Swift, provided by Ludovico Rossi.

- Added improved support for Windows.

  [libxlsxwriterCocoaExamples]: https://github.com/lrossi/libxlsxwriterCocoaExamples

## 0.1.7 September 27 2015

- Fixed Cocoapod spec file for iOS and OS X.


## 0.1.6 September 27 2015

- Added Cocoapod spec file to allow the library to be installed using
  [CocoaPods](https://cocoapods.org).
  Pull Request [#7](https://github.com/jmcnamara/libxlsxwriter/issues/7).


## 0.1.5 May 3 2015

- Added `worksheet_write_url()` function to write urls/hyperlinks to
  worksheets. See also @ref hyperlinks.c.


## 0.1.4 March 18 2015

- Added `worksheet_autofilter()` function to add autofilters to worksheets.
  See also @ref autofilter.c.


## 0.1.3 March 15 2015

- Added `worksheet_write_array_formula()` function to allow writing of
  array formulas in worksheets.


## 0.1.2 March 14 2015

- Added `worksheet_set_h_pagebreaks()` and `worksheet_set_v_pagebreaks()`
  functions to define worksheet page breaks.

- Added LXW_FOREACH_WORKSHEET() macro to allow iteration over all the
  worksheets in a workbook.

- Added `worksheet_set_print_scale()` function to set the scale factor for
  the printed page.

- Added `worksheet_set_start_page()` function to set the start page number
  when printing.


## 0.1.1 March 13 2015

- Added `worksheet_print_area()` function to control the print area of a
  worksheet.

- Added `worksheet_fit_to_pages()` function to fit the printed area to a
  specific number of pages both vertically and horizontally.


## 0.1.0 March 12 2015

- Added `worksheet_repeat_rows()` and `worksheet_repeat_columns()` functions
  to control the repeated rows/columns on printed worksheets.


## 0.0.9 March 9 2015

- Added `worksheet_gridlines()` function to show/hide screen and print
  gridlines.

- Added `worksheet_center_horizontally()` and `worksheet_center_vertically()`
  functions to center worksheet on the printed page.

- Added `worksheet_print_row_col_headers()` function to enable printing of row
  and column headers.


## 0.0.8 March 8 2015

- Added support for worksheet headers and footers via the
  `worksheet_set_header()` and `worksheet_set_footer()` functions. See also
  @ref headers_footers.c.


## 0.0.7 March 7 2015

- Added the `worksheet_merge_range()` method to merge worksheet cells. See
  also @ref merge_range.c.


## 0.0.6 March 5 2015

- Added the `workbook_define_name()` method to create defined names and ranges
  in a workbook or worksheet.


## 0.0.5 March 6 2015

- Added `worksheet_select()` function to set worksheets as selected.

- Added `worksheet_activate()` to set the active worksheet.

- Several portability fixes to fix warnings with different compilers.


## 0.0.4 March 1 2015

- Added `worksheet_set_margins()` function to set top, bottom, left and right
  margins in a worksheet.

- Fix for issue where format objects were written to the file in the order of
  creation rather than the order of use. This issue caused incorrect formats
  in cells.
  Issue [#3](https://github.com/jmcnamara/libxlsxwriter/issues/3).

- Fix for issue where tmp files in `constant_memory` mode weren't closed
  until application exited.
  Issue [#1](https://github.com/jmcnamara/libxlsxwriter/issues/1).


## 0.0.3 January 7 2015

-   Added worksheet page setup methods.

    -   `worksheet_set_landscape()`
    -   `worksheet_set_portrait()`
    -   `worksheet_set_page_view()`
    -   `worksheet_set_paper()`
    -   `worksheet_print_across()`


## 0.0.2 June 26 2014

- First public release.


## 0.0.1 June 8 2014

- First GitHub release.


*/