[doc] hordedoc alt tag generation

[Eric Rostetter]

Working on the userguide part of the hordedoc module.  When I run make
to get the web output, there are no alt tags generated for the images.

Anyone have any ideas of either what I'm doing wrong in the docbook code
or what is wrong in the generation scripts/stylesheets that we are not
getting alt tags?  I think my docbook stuff is correct, though I've seen
a couple of variations on it, so I'm not 100% sure.

-- 
Eric Rostetter
The Department of Physics
The University of Texas at Austin

Why get even? Get odd!