Don't use BGRA for upscaled textures.

Since they aren't color swapped.  Fixes #5881.
Ignore uncached/kernel bits in texture cache.

Although I suppose we could respect uncached and never cache...

Possibly #5879.
Merge pull request #5883 from unknownbrackets/texcache

Ignore uncached/kernel bits in texture cache
Merge remote-tracking branch 'origin/master' into master_0.9.8