[meta-sig] Transfer of XML-SIG and DB-SIG ownership

[Andrew Kuchling]

I'm still listed as the coordinator for the XML and DB SIGs, even
though I no longer actively use the technology that's the focus of
either SIG.  It's obviously a better idea to have an actual user or
developer as the coordinator, so I asked for volunteers to take them
over.   

Andy Todd <andy47@halfcooked.com> will be taking over the DB-SIG.
Rich Salz <rsalz@zolera.com> will be taking over the XML-SIG.  
I've already added them as owners of the mailing list, so I think the
only change is just to update the table at sigs/index.ht.  (While
you're at it, the references to the PSA could also be edited out of
that page.)

For now I'm still the owner of the catalog SIG.  That SIG is pretty
dead, so being the owner doesn't occupy much time, but if someone else
wants to take over it, I'd happily let it go.

--amk