SED Data Model working draft

[Douglas Tody]

Hello DM folks -

The SED data model working draft has been extensively revised to reflect
the architecture change we had in mind by the introduction of the
Spectral DM 2.0, the draft for which Mark just announced several days
ago.  The two should now be consistent with each other.  SED has been
simplified quite a bit by basing it on SDM, and issues such as the
confusion between SED and Spectrum should be much clearer now.

Until the draft document appears in the document repository you can find
it on the SED DM page, at

     http://wiki.ivoa.net/internal/IVOA/SedDM/SEDDM-20121015.pdf

Comments as always are most welcome.  I expect that both SEDDM and the
SpectralDM will be updated after the interop to relect any discussion,
and maintain consistency.

Cheers,

 	- Doug