Add scala-refactoring to the community build.

I wasn't able to run the script locally (tons of EXTRACTION FAILED). I also just updated the build.sbt in scala-refactoring to build with Scala 2.11, but this isn't in a release yet so I target that specific commit.
Ok. Could you add a short note about it? The next guy looking at this will know that we can upgrade to stable tag as soon as it contains that commit.