try to move all tests to Scalatest framework
remove more cruft and add tests for [im]muttable.LongMap and AnyRefMap
Multiple changes:

- Bring back tests for Enumerations

- Add Kryo serializer for AnyRefMap that is available with Scala-2.11.
  It is:
    30% faster than immutable maps
    50% faster than AnyRefMap when serialized with the generic map
        serializer

- Split version specific sources and tests in separate directories and
  instruct sbt to build the right ones

- Added tests for AnyRefMap and [im]mutable.LongMap in Scala-2.11

Remaining fixes: bring back Tupple serialization tests. The problem is
that inheriting tupples was deprecated
remove depencencies on junit-iterface: we do not use it anymore
Add back tuple serialization tests
More test cleanup and restructuring - drop java
Add specialized serializer for mutable maps

It's generic and produce the exact output type as the input. So
we drop the ScalaAnyRefMapSerializer because it is just a special
case of the generic one
Merge back everything into one tree that does not depend on versions

The only version dependent code is the AnyRefMap test that depends
on Scala-2.11. Also embedded there is immutable.LongMap for coverage
Merge branch 'fix-tests':

- All test are ported to Scala and ScalaTest and cleaned up

- Added version specific test for mutable AnyRefMap and LongMap
  available with Scala-2.11

- Added generic serializer for mutable Map-s that performs better
  than using the generic serializer for mutable maps. For some
  optimized Maps it performs significantly better

- Some tests were removed because they were testing depecated
  features: inheritence of tuples