Make it possible to force a static h261 quality level by pref
Merge branch 'h261' into h261-performance

Conflicts:
	media/webrtc/trunk/webrtc/modules/video_coding/codecs/h261/h261.gyp
	media/webrtc/trunk/webrtc/modules/video_coding/codecs/h261/h261_impl.cc
Fix build broken by H261 gyp file
Fix Preferences namespace in h261 encoder
Merge branch 'h261' into h261-performance