EXT-7504 WIP Force decloud after timeout using lower res textures

EXT-7626 FIXED LLTexLayer header file cleanup
EXT-7628 FIXED Don't cache lower res baked textures

Added more information into the texture debug view.
Mangled hash when uploading lower res baked textures so they're not cached
Lots of superficial cleanup on lltexlayer and associated classes.  Removed some unused functions and member variables as well.