Updated the TextureAtlasEncryptionTest to show how to use the ccSetPvrEncryptionKey(…) function.
Updated the notes and header docs for improved clarity.
Rename PVR decryption functions and variables to better fit in the Cocos2DX framework.
Improve log error notes.
Update TextureAtlasEncryptionTest to match revised function call in ZipUtils.
Update ccSetPvrEncryptionKeyPart documentation to clarify that encryption is never 100% secure.