VAAPI: Add VPP class which handles bob deinterlacing
VAAPI: Integrate VPP into VAAPI implementation
VAAPI: Use shared_ptr::unique() instead of use_count()
VAAPI: Update VPP class to support multiple deinterlacing algorithms
VAAPI: Integrate VPP changes into existing vaapi code
VAAPI, squash me: topField is no longer bool
VAAPI, squash me: Propperly clear the buffers on failure
VAAPI, squash me: Require a valid frame
VAAPI, squash me: Forgot one while generalizing from bob
VAAPI, squash me: Use CSingleLock in InsertNewFrame
VAAPI, squash me: Remove WaitForOutput and associated condvar, more CSingleLock, some minor polishing
VAAPI, squash me: Prepare for future renderer feature