Add RTCP packet class.
Adds packet types: sr, rr, bye, fir.

BUG=2450
R=mflodman@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/8079004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5592 4adac7df-926f-26a2-2b94-8c16560cd09d
8 files changed