Merge remote-tracking branch 'origin/4.5.0' into waterml

Conflicts:
	pom.xml
Finished adding xmlbeans mapping. Needs lots of testing though.
Wrestling with xmlbeans.
Made progress with xmlbeans!
I solved the substitution group and duplicate namespace declaration issues.
* The documents I'm generating aren't valid WaterML2 because om:procedure is missing. David Valentine pointed that out too.
* Now that I've got this working, there's a LOT of cruft I can rip out now. I just wanted to do this commit before I started ripping.
Addressed all of the issues in David Valentine's email.
* Need to test more. Validate with both schema and schematron.
* wml2:generationDate probably isn't necessary now that I'm including om:resultTime.
Output is now fully valid.
* Lotsa refactoring next.
* One possible issue with wml2:interpolationType.
The last tweak to the encoding, before I start refactoring.
Nuked a ton of old code.
* For safety, I want to commit these changes before I rename the "ogc2" package to "ogc", and rename all of its classes to remove "NC_".
Massively simplified waterml module. Lots of cruft removed.
* Some finer-grain refactoring remains.
Renamed the mapping classes. Refactored ID generation.
Improved clarity of the mapping classes.