fix for instoppable loop in mod_imap.c

[Brian Behlendorf <br...@hyperreal.com>]

In doing some actual try-all-cases testing on mod_imap.c I uncovered a
hole which would allow mod_imap to spin in a loop forever.  It's in the
logic which resolves "../" in links in map files, and what happens when it
hits the base case, "/".  So, there is now officially this and a call to
imap_url change which constitute my changes to the mod_imap.  I may find
more, I haven't even gotten into config file options yet (though all other
cases appear to work fine.)

By the way, those of you who have used imagemaps and polygons a lot - have
you ever had trouble with concave polygons?  Howbout with ordering of
points (clockwise vs. counter-clockwise)?  Some in-the-polygon algorithms
require knowlege about direction, and I left my Foley/VanDamm at home...
(er, maybe that's a good REASON to go home, eh?)  Someone sent me a
50-polygon map which was giving some erroneous connections and I think
that might be it.  

	Brian