[relax-ng] New draft

[James Clark <jjc@jclark.com>]

I've put a draft reflecting our decisions at the last telcon at:

http://www.thaiopensource.com/relaxng/spec.html

See 7.1.3 and 7.4 for the changes.

Murata-san observed that there was a potential confusion in the use of the
term "mixed content-type" in section 7.2, since it covered XML 1.0 element
content as well as XML 1.0 mixed content.  Rather adding a note, I have
changed the terms: it now uses "complex content-type" and "simple
content-type" instead of "mixed content-type" and "data content-type".

I've also fixed a few typos.

Now would be a good time for people to do a careful proof-reading of this.

James