Make vaapi decoder compatible with latest libva changes
Modify vaapi decoder to choose the format used by vaapi.
This avoids possible double format conversions if the output or encoder expects a diffrent format.
Add vaapi h264 encoder
Disable DRM for now
Use fast cached SSE4.1 copying for vaapi-enc
Preparations for VPP
Add deinterlacing code
Finalize Deinterlacer
Fix trailing endings
Upload picture on push to stack
Add option to switch between VAAPIs native format or VY12
Add option do de/activate deinterlacer
Generate more idr-frames, so the stream becomes seekable
Variables cleanup