Fixed implicit operator.
Fixed to match XNA behavior.
Some cleanup.
Fixed incorrect defaults in TextureProcessor().
Fixed bad mipmap generation on compressed textures.
Added shared TestProcessorContext and TestContentBuildLogger for testing pipeline stuff.
Implemented overwriteExistingMipmaps in TextureContent.GenerateMipmaps().
Added some initial TextureProcessor tests.
Merge pull request #3082 from SickheadGames/mips

TextureProcessor Fixes and Tests