Call "make html-doc" from here or one directory above.

yorick has to have been built, unless the YORICK= variable is used to
select another yorick.

A decent texi2html must bee installed (see Makefile).

Use PLATFORM=(mac|win) to select version of the "Installation
Instructions" README.html.

This creates the HTML hierarchy under compiled-doc/ (unless TO= is
used to select another top-level directory):
 README.html     Installation Instructions
 doc/README.html Getting Started
 doc/html_xref   Cross-referenced DOCUMENT comments
 doc/manual      The Yorick Manual
 doc/refcard     Quick Reference Cards
 doc/images
 doc/skull.css
 doc/style.css

The "install" rule copies this hierarchy to DESTDIR (default:
/usr/local/share/doc/yorick).

The pdf documentation is copied over, but not the text documentation
(*.doc, FILE_FORMATS...)

skull.css, style.css still broken on IE 6 (10/Apr/07) because of
IE bug involving    position: fixed
-- needs to become   position: absolute
