XMI12 — Editorial: Fix up the cross-references.

There are a number of missing and broken cross-references in
ad/99-10-02.
For example:

• the Glossary refers to "MOF 1.x",

• the Compliance chapter contains references to [SAX reference],
  [XMI reference] and so on.

• the Compliance has a cross reference to "Section ." (sic) and
  to "rulesets in Section 6" which should be 7.

And so on.