Re-enabled peerconnection initialization. Upgraded to akka 2.2.1. Replaces some slf4j logging statements with actorlogging. Switches akka serialization to use kryo library.
Removes sessions controller since all session creation logic was just moved into main signal controller. Fixes problem with cookie not getting used when angular was making requests. Moves serialization into common package. Removes unused classes. Creates ClientWrapper actor that gets used to mediate requests between atmosphere and the user as well as the signaling and media server.