better desktop file editor, presents more space in less space!

better desktop file editor, presents more space in less space!

 * use toolbook and segment all information to different pages

 * icon got its own page, with bigger view

 * labels on one line, entries on the next: more consistency, better
   alignment, takes less horizontal space and allows entries to show
   more characters.

 * editing new desktop files (Settings > Apps > New Application) will
   use a dynamically created name based on application name, instead
   of falling back to a numeric based _new_app-%d.desktop.

SVN revision: 46902