Update MiMa to SBT 0.13.0 and Scala 2.10.2

 - Updates Specs dependency, and explicitly includes Mockito and JUnit
 - Updates tests for changes in scalac (no more ScalaObject, and case
   class copy methods for abstract case classes.)
 - Depends on scala-actors. We should update this. Or, see if the GUI is
   actually used and think about deprecating it.
 - Accounts for removed methods from the stdlib and inference changes
   due to the addition of Option.flatten.
 - Update to SBT 0.13.0. The build has not been refactored to take advantage
   of this yet.

Review by @dotta