[ebxml-msg] Issue 56: Specification / Schema conflict resolution

We need to choose a "winner" when (as will inevitably happen) the words of the
specification disagree with the separate schema instance.  My suggestions make
clear choices rather than leaving things open.  Further, we need to choose a
winner our programs can implement without conflicting with a normative
deliverable from our group.  We provide a schema that arriving messages will
be checked against before the application even hears about it.  Therefore, it
will win and that must be reflected in our documentation.

thanx,
    doug