First attempt at cross building for 2.10.x and 2.11.x

- ran into issue with overloads with default args
Merge branch 'develop' into topic/2.11

Conflicts:
	project/Build.scala
	project/build.properties
eliminate more 2.11 warnings

- provide return types for macros
- use `Future.apply` rather than `future`
- don’t use NotNull
- turn off deprecation warnings for macros due to 2.11
- don’t use global exec context in schema manager
remove use of DWrapper in Fact.add and Fact.retract
refactor DWrapper

- remove need for DatomicTypeWrapper trait
- annoyingly, still need the DWrapperImpl trick
bump version numbers

- remove JUnit from specs2 tests
Merge pull request #110 from pellucidanalytics/topic/2.11

Can't compile against 2.11