Adding a factory to remote bitrate estimator and allow it to be set via config.

Additionally:
 - clean api to set remote bitrate estimator mode.
 - clean api to set over use detector options.

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

Review URL: https://webrtc-codereview.appspot.com/1448006

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4027 4adac7df-926f-26a2-2b94-8c16560cd09d
21 files changed