More trace events

The goal of this change is to unify tracing events styles
and add trace events for all RTP traffic.

BUG=1555
Review URL: https://webrtc-codereview.appspot.com/1290007

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3806 4adac7df-926f-26a2-2b94-8c16560cd09d
20 files changed