XLink changes

Bob asked to see the changes associated with fixing XLink. So two
things:

1. Here they are:

  https://github.com/docbook/docbook/commit/c903e3a4b81ff59c64a676a11cb9709aff6df1dc

2. Yes, I moved all the schemas to github. I didn't ask for
   permission. I didn't consult anyone. I accept full responsibility
   for doing something that you might consider rude.

But github is *so* much nicer than Sourceforge and features like the
ability to publish links like the one above persuaded me to do it.

The repository contains all of the history from the Sourceforge days
and I kept it private for a while. But really, that link is so
positively, hugely useful, that I flipped the switch and made it
public.

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <>      | Birds are taken with pipes that
http://www.oasis-open.org/docbook/ | imitate their own voices, and men
Chair, DocBook Technical Committee | with those sayings that are most
                                   | agreeable to their own
                                   | opinions.--Samuel Butler