BUG-582: use QNameModule when instantiating QName

Instead of instantiating internal QNameModules, just create one and
reuse it.

Change-Id: I3db8c7ffc57258621eea2bc052c16bb3c3a33bce
Signed-off-by: Robert Varga <rovarga@cisco.com>
Merge "BUG-582: use QNameModule when instantiating QName"