gst-plugin-cedar: import PoC gstreamer 0.10 plugin

GStreamer 0.10 plugin for Cedar H264 hardware encoding with no
binary blobs.

Based on PoC h264 encoder by Jens Kuske:
https://github.com/jemk/cedrus/tree/master/h264enc

Tested on OLinuXino A20 micro, kernel sunxi-3.4

Signed-off-by: Enrico Butera <ebutera@users.berlios.de>