Add some more docs and a command line program.
For some reason, need to move the imports inside generate() or else they are they are not seen(?)
Add copy of GDML schema 2.3.0 and test.gdml from PyGDML 1.2.0 and some test code to validate it - which fails.
Change spelling so file validates against GDML.
Produce valid GDML in test and validate it.
Checkpoint.
Validate gdml explicitly if desired, not on dumps().  Fix some bugs.
Assert on TGeoManager to catch failures.

Valid GDML still makes ROOT choke.
WIP
Slightly further.
Making ROOT matter is tough.  This is broken right now.
Ignore ROOT's element table, retain a semblance of sanity.
Push a little further.
Mention how to get ROOT on Ubuntu.
Remove class name from config after it is used so it doesn't find its way into configure()
Explicitly convert single quote to double quotes to make all but the most recent ROOT GDML interpreter happy.
Allow for post placement of daughters and fix gdml if no pos/rot given.
First commit
Order volumes as they are emitted by GDML to make ROOT's fussy GDML importer happy.

Also add docs how to use GraXML to view GDML - it isn't as fussy.
Add builder.defaults simplification, add Boolean support.