large set of updates converting some of the textdocs to SGML/DocBook.

large set of updates converting some of the textdocs to SGML/DocBook.
I think these were originally from Jelmer, but I've lost
the original message.

Also had some syntax errors in the manpages (does no one regenerate
after making changes to the SGML source?)

Still have some developer specific docs to add from Jelmer in the next
go around....
(This used to be commit 5f673b788314325699a64377d514dda435e6c478)