Updating to new ManagedPVRTC library.
Updating MonogameContentProcessors to new ManagedPVRTC library.
Merge branch 'develop' into UpdatePVRDependency
Removing old PVRTexLibC solution.
Removed reference to old PVRTexLibC library.
Merge pull request #1486 from SickheadGames/UpdatePVRDependency

Updating to new ManagedPVRTC library.