#2052 - Revise gallery.show_full_size.js: update for new jQuery, refactor.
- fixed for new jQuery.
- removed unnecessary CSS.
- fixed bug where small images would get oversized when the window was resized.
- refactored a few other things.
Merge pull request #203 from shadlaws/fix_2052

#2052 - Revise gallery.show_full_size.js: update for new jQuery, refactor.