Fledgling 'run task' support.  Tests are failing epicly, need to investigate.
Adding the ability to serialize task results back.

* No proper error handling yet
* Added Atributed[_] as a class we can serialize
* Added sbt's "collection" library as a requirement for sbt-rc-remote-controller artifact (for Attributed[_] serialization).
* Added a test for task serialization.

Review by @skyluc