Play 2.1 & Scala 2.10

Hi @sihil - I added on to your Play 2.1 work and rebased against the latest version of master.

All dependencies now resolve in SBT, but there are still quite a few compilation errors. I started trying to attack the Akka stuff (see https://github.com/guardian/deploy/commits/ignorant-attack-on-akka) but got out of my depth so I thought I'd defer to you to sort that lot out... :sparkles: