VAAPI: Add VPP class which handles bob deinterlacing
VAAPI: Integrate VPP into VAAPI implementation
VAAPI, squash me: Use shared_ptr for vpp thread
VAAPI, squash me: Changes to VPP, to better support runtime re-init
VAAPI, squash me: Forward diffrent deinterlacing methods to ui, so the user can select a method
temp hack, keep core file
VAAPI, squash me: Probe VPP only if unknown
VAAPI: Hack to fix occasional crashes on stream start