This is a developmental snapshot of the XML-based "ncxgen" routine.
It uses the SAX XML parser "expat" (aka "libxmltok") from James Clark.

This version will read an XML file produced by ncxdump and produce
a (known-buggy) .nc file.  It does not handle character and byte data
particularly well, but the problems appear to reside in the NetCDF
code, not the XML code.
