Wayland/Weston VAAPI backend.

Weston has a backed (weston/remoting) for sending a Jpeg stream to another computer using RTP. I want to use VAAPI in order to get an H.264 or H.265 stream instead. This must me zero copy otherwise it uses to much PCI bandwidth otherwise.

The bottleneck with these things is bandwidth. Using VAAPI saves GPU to CPU bandwidth. Using a good video codec saves Ethernet bandwidth.