A few locking changes

1. The Monitor class was essentially doing nothing because the scoped_lock objects weren't actually locking any supplied mutex.  Also, locking before a function call is a bad idea because the bounds of the lock are indeterminate, so do not lock there anymore.
2. Remove the writeMutex_ in WebRtcConnection; it was only protecting a single method that doesn't need protection
3. Remove some unused stuff.
Change WebRtcConnection to use webrtc's fec if necessary

because firefox doesn't support RED/FEC, licode was converting RED/FEC to raw VP8, but it was doing this for everybody, regardless of whether or not they could digest red.  change it so for endpoints that can digest red, we send it straight through.  For those that can't, we use WebRTC's FEC handling to recover missing packets.
Merge pull request #192 from jnoring/improvements

Improvements