Update v2.6.3

This is a small bug fix / enhancement update. 😀

• Updated help info for this functionality to reduce confusion on how the previously added Selection Spritesheet function works.
• Added a warning / error check / reminder that the frames must be included in a tag in order to be included in the Selection Spritesheet.

Also added in a theme debug mode (hidden) which helps set up dialog sizes more easily for any new themes that are requested to be added.

Hope your all having a wonderful day! 😀