Folks,

Enclosed is a patch for a re-written equation parser.  During 
EuroBSDCon, I wrote an eqn_html.c that produced beautiful equations in 
MathML.  However, I noticed that the parser didn't account for grouping, 
thus,

  a sub b over c

would have grouped as "a with a subscript b/c".  Unfortunately, this is 
correctly "a with subscript b, both over c", where the "under" groups in 
the other direction.  With the new parser, this is all handled properly.

It also significantly simplifies the eqn_html.c code, which I've updated 
as well.

The patch ONLY modifies the logical parse: the physical parts, like 
token parsing, definitions, and so on, are all carried from the old code.

I've run it over all examples in the various eqn documents out there 
without issues.

Thoughts?

Best,

Kristaps