* (bug 31878, bug 31542) Fix XML namespace output in API; removed now-unneeded includ...

* (bug 31878, bug 31542) Fix XML namespace output in API; removed now-unneeded includexmlnamespace parameter.

Any existing uses of includexmlnamespace should be ignored and harmless.

If output data already includes a specific default namespace as an xmlns attribute, it is now retained -- so for example the RSD API discovery module outputs the appropriate namespace instead of the generic API one.

Partial revert of r99135 which added the includexmlnamespace parameter as a temporary requirement to get the xmlns attribute included.

Followup to r88007 which added the xmlns originally, but in the wrong order so it overrode existing output data.