Scala 2.11 cross build

finagle-http does not have a 2.11 published version so newman-finagle does not have a 2.11 version. There doesn't seem to be a way to exclude projects from being built for a specific scala version, so I had to make some new tasks: testCross, publishCross, publishLocalCross, publishSignedCross. They should be used instead of the default task ie. instead of +test use +testCross

This patch also includes #112 as it is dependant on it

fixes #109