Add tests for StringDatumConverter.
Add tests for BoolDatumConverter
Add tests for DoubleDatumConverter
Add TupleConverter and ArrayConverter tests.
Add exception coverage to Bool, Double and String converters.
Add AggregateDatumConverter tests.
Add AnonymousTypeConverter tests.
Formatting cleanups.
Add null datum test case.
Revert accidental change.
Move DatumHelpers to test assembly.
Merge pull request #140 from tetious/datumconverter-tests

Unit tests for IDatumConverter implementations, fixes #60