Release 2.1.7

* This version fixes peer-to-peer publishing and subscribing
  issues between iOS and Chrome.
* This version fixes memory leaks in OpenGL rendering.
* This version fixes issues when disconnecting from a session.
* OpenTok support for [TURN over TCP](http://www.tokbox.com/blog/opentok-now-supports-turn-over-tcp)
  is not currently available in iOS.