1.20 - Added support for using 3 spaces in addition to tabs for
       parameter descriptions.
       Added support for GNU -p, --param descriptions, for easier
       GNU parameter support.
       Fixed help description bug with [ditto] of single parameter flags.

1.13 - Fixed bug that would always match parameters in a case insensitive
       way, as if [nocase] had been used.  This should speed the parser a 
       tiny bit.

       [cluster: ...] was incorrectly being printed in help usage.

1.12 - Fixed bug with :+i, :+n, :0+i options not being cast appropiately
       when used in pvttypes.
       Added [debug] option to argument description to turn on debugging.

       NOTE: there is a known bug when using [] within pvttype regex
       definitions.  Problem seems to be related to DelimScanner/strscan.

1.11 - Fixed a pretty bug that was parsing -flags inappropiately and leading
       to slower parsing.