Upgraded to Play 2.3.0-RC2

* Added cross build support for Scala 2.11
* Updated a few other library versions
Use Play actor system

Fixes #88

By using the Play actor system, we avoid the thread leak created by not
shutting the mongo driver down.

Also, made sure the mongo driver is shut down.
Merge pull request #88 from jroper/fix-thread-leak

Thread leak - driver doesn't get shut down on stop
Merge pull request #87 from jroper/play23

Upgraded to Play 2.3.0-RC2
update readme for 0.10.5.akka23-SNAPSHOT
update to play 2.3.0
Change sonatype URL to HTTPS