Added sbt-scalariform plugin.
Merge branch 'cowboy129-master'

Conflicts:
	src/main/scala/spray/contrib/socketio/LocalConnectionActive.scala
comments.
code formatting.
Namespace accept Subject[OnData] as the subsriber instead of
Observer[OnData].
Let sessionId can be generated by a sessionIdGenerator.
Simplified implementation of topic subscriptions
Rename ClusterNamespaceMediator to DistributedBalancingPubSubMediator, and no need to be singleton now.