Issue #218 - Move resolving of constructor and parameter names from the ...

...code run by the executor back to the application

- AnyObjectFactory computes the resolved constructor parameter type names and stores them in a serializable field. After deserialization, it finds the proper constructor which signature matches the stored type names.
- Added CassandraRDDReplSpec for testing CassandraRDD behaviour in REPL - for now, the tests are ignored because of some problems
- Added Scalactic to the dependencies of tests
- Added SBT plugin which allows to show the dependency tree of a module

Fixes #218
Why Either? Isn't Class[_] sufficient?