Added tile animation editor

Allows editing tile animations by drag & drop.
Implemented deleting of tile animation frames
Added option to disable playing of tile animations
Made undo/redo shortcuts work in tile animation editor

Also update the frame list as appropriate and make sure only one undo
command is created when deleting multiple non-consecutive rows at once.
Made animated tiles recognizable in the tileset view

By rendering a film strip on top.
Lua plugin: Support tile animations and image collection tilesets
JSON plugin: Added support for tile animations