Small change to mglyph

After trying to implement mglyph's valign attribute, there was confusion as
to the meaning of "top", "middle", and "bottom".  It was unclear from the
spec what they are meant to align with.  The spec language was particularly
confusing because mglyph is inside of a token element such as <mo> and so
the siblings are other characters (if any) in the token, but the spec
referred to sibling mrows (if any).  Additionally, the spec refers to valign
changing the baseline, which sort of contradicted what those values meant.
We decided that since the wording wasn't clear, the values should be
removed.

The updated spec can be found at:

http://monet.nag.co.uk/~dpc/draft-spec/chapter3-d.html#id.3.2.1.2.2<http://monet.nag.co.uk/%7Edpc/draft-spec/chapter3-d.html#id.3.2.1.2.2>

http://monet.nag.co.uk/~dpc/draft-spec/appendixa-d.html#parsing_mglyph<http://monet.nag.co.uk/%7Edpc/draft-spec/appendixa-d.html#parsing_mglyph>

If someone who has looked at this does not agree with the change, please
send email.


Neil Soiffer
Senior Scientist
Design Science, Inc.
www.dessci.com
~ Makers of MathType, MathFlow, MathPlayer, MathDaisy, WebEQ, Equation
Editor ~