Add scala 2.11 test/build verification.
* Add 2.11 build configuratoin to travis ci
* Create command which runs `safe` unit tests
* Create command to test the scala 2.11 build
* Update scalacheck to 1.11.4
* Update specs2 to 2.3.11
* Fix various 2.11/deprecation removals
and other changes.
Fix eval test failure in scala 2.11 with XML not existing.
updated compile tests for new minimal AnalysisCallback
moved discovery to discovery/ subproject and updated for new approach
fixed discovery to only find public methods when searching for annotated definitions
extracting inherited definitions unimplemented in api/, so some discovery tests fail
moved discovery classes from sbt.inc package to sbt.compile