This is a quasi-working NetCDF <-> XML toolset.  It requires "libxmltok"
from James Clark's expat library.

I have created a new DTD, based upon feedback and increased experience
with other DTDs.  The element <value> is intended to act as a legacy
comma-delimited format, with additional formats added in the future.
Alternately, we may reach a consensus that the benefits of using smaller
buffers warrant an immediate definition of <1d-array>, <2d-array>,...
elements.  This would greatly increase the size of the XML files, of course.
Also, remember that <value> is also used in the attributes element since
arrays are permitted there as well.

It is known that XML->NetCDF character and byte data is flaky, but I 
believe that the error is in the NetCDF side of the problem, not the 
XML parsing side.  I'll continue looking at it, but I expect other tasks
to bump it off the top of my stack for awhile.  Someone else should look
at the code anyway - it's been several years since I've used NetCDF much
and it's certainly possible that I've made a stupid error or three.
