Add working links to main doxygen summary page.

On why I had to use such a verbose syntax to make the links
work, see this:

http://stackoverflow.com/questions/2499128/using-namespace-for-doxygen-comments

The links to afw classes are still not working, even though
they should via Doxygen tags.  But I've left them in in the
hopes they will work in the full-stack Doxggen build.
Rename Task pages to avoid reference conflicts with class pages

Having a @page and a @class with the same name confuses
Doxygen.
Add missing documentation for function arguments.