Changed the UI to use JMenuBar instead of having buttons inline with the region list.
Moved the window creation code into some smaller functions.
Made it so that you can read the license by going to "General" and clicking "license". The license is read from the license.txt and should be kept in sync with LICENSE
Fixed a issue that prevented the window from being resizable.
Fixed exception acquiring when clicking delete or backspace on the region list when it's empty.
Added the ability to add a grid of regions.
Fixed a null pointer exception when saving a atlas file and there being no image loaded.
Made the license dialog wide enough to display the license without a horizontal scrollbar.
Changed it so swing uses the system look and feel.
Made swing use the system toolbar on Mac OS X.
Fixed that cell height could be below 1.
Fixed that the temporary region was visible on launch.