Remove VideoEngine class from new VideoEngine API.

The VideoEngine class had minimal use, so it makes more sense to bake
its functionality and config into VideoCall for a simpler API. The only
thing the VideoEngine class could do was to create VideoCalls.

BUG=2224
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2020004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4543 4adac7df-926f-26a2-2b94-8c16560cd09d
9 files changed