[PATCH] Add minimum version check to mailer.py

Here's a quicky take on what I was thinking in terms of making mailer.py
verify that it is being used with a new enough version of the Subversion
 Python bindings. It's basically the same kind of thing I put into ViewVC.

Thoughts?

-- 
C. Michael Pilato <cmpilato@collab.net>
CollabNet   <>   www.collab.net   <>   Distributed Development On Demand