gcalc semi-final

[Gregory Leblanc <GLeblanc cu-portland edu>]

Aside from removing the comments from this, I think it's just about
finished.  I haven't taken a good look at how it render in the GHB (it's
segfaulting on all of my machines today), but as far as I can tell, the
DocBook is at least correct.  I know that the examples don't look all that
good, but I'd really rather not muck with it in the source, but rather in
the stylesheets.  If I don't have any comments, concerns, or questions in a
couple of days, I'll forward these on to George for either a final technical
review, or just addition into CVS.  Later!
	Greg