updating to akka/play 2.2
buffer progress until someone is listening (progress messages may happen before websocket connection was requested)
Merge branch 'akka2.2'

Conflicts:
	.idea_modules/scastie-build.iml
	.idea_modules/scastie.iml
	project/ApplicationBuild.scala
	renderer/src/main/scala/com/olegych/scastie/PastesActor.scala
update play and akka
cleanup dependencies