Documentation fixes: autolinking

Three small patches that fix  autolinking errors in the documentation.
The first two  escape the autolinking syntax in a  few places where it
was not intended to  be a link.  The third fixes a  few places where a
link was intended but the autolink syntax was not quite right.

    http://starurchin.org/dillo/patch/doxygen-escape-hash-characters.html
    http://starurchin.org/dillo/patch/doxygen-escape-double-colons.html
    http://starurchin.org/dillo/patch/doxygen-fix-simple-name-refs.html

Comments are welcome.

If these  are OK I  can push them myself  as I have  write permission.
(It's actually easier for me to  do it myself because Mercurial Queues
does  not notice  when  the  remote repository  has  a  patch that  is
identical to a patch in its queue and generates spurious errors.)

Regards,

Jeremy Henty