Minor updates to build files, versions etc

It didn't build out of the box for me as-is using play 2.1-RC4, so I simply refreshed some versions etc, might be useful.

p.s. I have no clue why adding the  "org.slf4j" % "slf4j-api" % "1.6.6" dependency did the trick, but without it, I couldn't get it to compile. not sure if it's local only for me or not...