Remove catman(8): it's superfluous.

Remove catman(8): it's superfluous.
Users of man.cgi should be able to just copy in their directories and have
the CGI fine everything on its own or just suck it up or, in the cases
of multiple manroots, have a simple config file.
Besides, now that mandocdb(8) is using relative paths for everything,
needing a fancy "cp -R" is silly.