Making RemoteRateControl::min_configured_bit_rate_ configurable

The minimum bitrate can now be configured from WrappingBitrateEstimator.

BUG=2698
R=stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/5699004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5279 4adac7df-926f-26a2-2b94-8c16560cd09d
11 files changed