XML Handler

[csreades]

A number of issues with the XML functions in the state environment.

• Successive "RemoveAttribute" calls result in:
  "
  Exception thrown: read access violation.
  this was 0x68.
  "
• SaveToString calls once an attribute has been removed and then added throws the same error
• SaveToString calls can duplicate "xmlns=..."

This error can be repeated by including an XML file in the resource folder and using this code:

	auto xml_string = pStateEnvironment->LoadResourceString("test");
	auto xml_object = pStateEnvironment->ParseXMLString(xml_string);
	auto xml_string_back = xml_object->SaveToString(false);