Gstreamer VDPAU support

by Carl-Anton Ingmarsson for GStreamer

Many of todays video cards have built in decoders for a lot of different formats. By adding support for these decoders to Gstreamer, we'll enable playback of HD content on CPU limited hardware where it otherwise would have been impossible. It will also help to unburden the CPU on more powerful hardware so that you for example could compile the Linux kernel while watching your favorite movie.