Based upon Chat example from Atmosphere repository.
Main differences:
- The Play Application is of Scala nature (PlayScala plugin instead of PlayJava)
- the Global object falls back to standard Play Router if there is no matching Atmosphere handler
- the Atmosphere managed handler is implemented in Scala (ScalaChat)
- the handler does not return outgoing Message directly but uses Broadcaster
- this is to demonstrate that the response mechanism does not need to be synchronous and the response can be sent from another thread