AXIOM-311:
* Generalize the TestGetChild/TestSetChild/TestSetChildVersionMismatch test cases so that they can be used to test getters/setters in SOAPEnvelope, SOAPBody, SOAPFaultCode and SOAPFaultSubCode as well.
* Remove old test cases made redundant by this change.
* Fixed a bug uncovered by the new tests.


git-svn-id: https://svn.apache.org/repos/asf/webservices/axiom/trunk@1606606 13f79535-47bb-0310-9956-ffa450edef68