UI Overhaul

*Converted Mipey's third-party Sprite Font over to the new official
Scirra Sprite Font, for future proofing and stability.

*Redesigned the UI System to not only utilize the new Sprite Font, but
also to use smaller textures and fewer objects that would be reused for
each individual menu, in order to increase speed and shrink filesize.
Instead of using 9 256x244 textures on a Sprite and 3 256x80/16/etc...
textures on another Sprite, Revahlen now uses 2 different 9-Patch
objects with 32x32 textures each, reused for every menu. See this
article on why this is an awesome thing that was worth the
paintstakingly tedious process:
https://www.scirra.com/blog/112/remember-not-to-waste-your-memory

* Just a few other small little fixes and changes.