[mod_python] mp_server.register_cleanup

Hi Grisha,

I'm back using mod_python, on a real project this time.
We've been using 3.0 beta for a few weeks and it works great!

Now I'm trying to use mp_server.register_cleanup, and that fails
with a "ValueError: first argument must be a Request object".

My first diagnostic (unless I'm doing something silly)
is that it's a remnant of mod_python 2.x,
since the Request class seems to have disappeared
from apache.py.

Is that an easy fix for you? 
Or should I dig it a little bit more?

-sbi