Tabs are now included as Class items in all themes, the OK button in ExportDialog appears on the left on Windows machines, and on the right in all other operating systems. Also added border outlines to all window dialogs.
You can now choose how many columns you want your spritesheet to be, allowing you to export atlases.
ISSUE: If the number of columns is larger than the number of rows AND rows * columns are not equal to the number of frames, the result is weird. The exported image has transparent space on its bottom side.
Made AboutDialog.tscn a scene of its own, added logo icons and names for the developer team, contributors and donors. Feel free to change/add things related to you!