Updated YAXSerializer
Updated YAXSerializer

Replaced string classNames with XNames to allow namespaces to be
specified. - All tests pass after modifications to XMLUtils and
StringUtils to match.
Updated to allow the creation of elements with custom namespaces. -
Passes all tests including new SingleNamespaceSerializationTest and
MultipleNamespaceSerializationTest.

gingsjo/YAXLib,sinairv/YAXLib,gingsjo/YAXLib