Misc changes to play2 tests

* Removed out of date play2 tests that don't have maintainers
* Moved play-slick into play2-scala directory
* Some code refactoring between play2-scala-anorm and play2-scala-slick
* Updated everything to the latest versions fo Play, Scala, etc

Cc @hamiltont and @donovanmuller. After this PR, the only remaining change is to update play-java-jpa and move it into into the play2-java directory.