Webware for Python

I finally did the new algorithm for serverSideInfoForRequest (which has
been broken for some time).  It's checked in, but won't be enabled
unless you add 'UseNewPathAlgorithm': 1 to Application.config (since it
may break things for people) -- the old algorithm is still there
untouched.

There's some cruft in dispatchRequest which should be removed if this
algorithm becomes the default -- FilesToHide and such -- which may have
been the source of the original problem (at the time I was trying to
debug the problems with extraURLPath, I didn't even know there was URL
munging going on in this dispatchRequest).

I don't know what the performance change is, but the new code is much,
much shorter.  Should be a maintenance gain.

I've encountered some weird stuff with the PSP tests -- but I think they
are already broken.  Anyway, I could use some help debugging this stuff
-- forwarding is broken, I think, but I don't know what the proper
behavior is.

This might be a nice place to start some automatic regression testing,
especially since it would have helped before.  Has anyone done anything
toward this yet?

  Ian