According to RFC 6120 8.2.3 7
An IQ stanza of type "error" MAY include the child element contained in the associated "get" or "set" and MUST include an <error/> child; for details,
Smack currently supports error IQs containing only the error child.
- Change IQ.getChildElementXML to possible return both elements (error and original)
- Add IQ.createErrorResponse(IQ request, XMPPError error, boolean includeOriginal)
- Add unit tests for this functionality