Video_decode: Check licenced codecs at component create
Video_decode: Check licenced codecs at component create

Check licence state of each codec at component create.
Only advertise licenced codecs through OMX_IndexParamVideoPortFormat/
MMAL_PARAMETER_SUPPORTED_ENCODINGS.
Do not allow OMX_IndexParamPortDefinition to be set to an
unlicenced codec type.
MMAL_IL code modified to return MMAL_ENCODING_WVC1 as first
match for OMX_VIDEO_CodingWMV. It's the main supported variant
on Pi.

raspberrypi/userland,adamheinrich/userland,6by9/userland,kraj/userland,kraj/userland,adamheinrich/userland,JamesH65/userland,JamesH65/userland,6by9/userland,kraj/userland,maroviher/userland,maroviher/userland,maroviher/userland,6by9/userland,raspberrypi/userland,raspberrypi/userland,JamesH65/userland,adamheinrich/userland