Speed up TextureCache::Invalidate() in debug.
Cache vertexes based on frames not draws.
Use backoff to invalidate textures as well.
Don't check the power of two padding in texcache.
Keep track of whether a texture is reliable or not.
Don't delete cache invalidated textures.

Note: still decimates.
Don't forget a tex is unreliable until decimate.
Merge pull request #647 from unknownbrackets/texcache

Improve texture and vertex caches