Move Scalding to 2.10/2.11

So this is just the beginning, but it's a big chunk of the work. I've been doing it between other things.

The big things I've done are to get scalding-core and scalding-hadoop-test working. Note: the DistributedCache tests in scalding-core had a dependency on mockito.... for now I commented it out. Do we want to depend on mockito just for one test? That said, rewriting is going to be a slight pain. So I'm not sure what we want to do there.

Either way, this is to get the ball rolling. I haven't started the 2.11 work becasue we need a new algebird release...but the scalatest migration stuff is enough for the time being!
should we use the an[xxx] approach or the intercept one? intercepts only advantage is getting access to the exception afterward. More i'm not sure we want to use both if we don't need to? not an issue though fine with this too.