Add PictureID and NonReference to codec information

The PictureID and NonReference information is now routed from the
encoder to the RTP packetizer through CodecSpecificInfo and 
RTPVideoHeaderVP8.
Review URL: http://webrtc-codereview.appspot.com/51003

git-svn-id: http://webrtc.googlecode.com/svn/trunk@155 4adac7df-926f-26a2-2b94-8c16560cd09d
11 files changed