Willscott ffoxwork

Unfortunately, this merge also includes unmerged commits on freedom_0.6.  Only the last commit is new though:

* removes need for core.peerconnection, which was used poorly in auth, and wanted core.rtcpeerconnection anyway
* removed a couple of ux issues that caused errors in firefox. the others seem less simple.
This was done at the time when @keroserene was trying to expose the rtc fingerprint and check it against a stored version. The last design discussions on crypto were to sign signaling messages, and then check them, at which point auth no longer needs rtc privileges. We can remove this file for now.