2010-07-07: 0.3.4 (tomk32-flickr_fu)
  * Added medium640 size (the new 'z' from flickr's brand-new broader layout)
  * Added attributes for height and width of original

2010-04-22: 0.3.3 (tomk32-flickr_fu)
  * Fixed bug where :extra fields received via photos.search where ignored in Photo
    and an additional API call was made
2010-04-17: 0.3.1 (tomk32-flickr_fu)
  * Allows to add extra fields to flickr.photos.search (and other in this flickr.photo)
    that are requested from flickr. This can be used to e.g. get the original_url quicker.