Spectrum Data Model

[Jonathan McDowell]

Following input from Doug Tody and Arnold Rots, I have completed new versions
of the Spectrum Data Model document:
  Version 0.96d   - some corrections to schema to match the software package
  Version 0.97    - an alternate version for discussion, with Frame and Coverage replaced
                    by STC and Characterization to match other DM group efforts.
We should discuss at Victoria which of the two approaches to push towards PR: a version
that is self contained or a version which depends on STC (the version of Characterization
is slightly different from the current draft and is contained within the document).

The documents are at http://hea-www.harvard.edu/~jcm/vo/docs/index.html
and at the IVOA DM group page http://www.ivoa.net/twiki/bin/view/IVOA/IvoaDataModel

 - Jonathan