handling /usr/local/lib/python2.x/site-packages in sys.path

[Matthias Klose <doko@cs.tu-berlin.de>]

Currently Debian's python has /usr/local/lib/python2.x/site-packages
in sys.path allowing for installation of local modules.  Barry did
point out that this conflicts with a python installation, where
/usr/local is the default prefix, and the system python gets modules
from the local installation.  Some suggestions were made to fix this:

 - add an env var to not include /usr/local/lib/python2.x/site-packages
   when the env var is set. Keeps standard behaviour without
   modifications and allows people to remove it from sys.path. But
   requires the user to know about that option.

 - add another path (e.g. /usr/local/python/lib2.x/site-packages),
   and remove the /usr/local/lib/python2.x/site-packages path after
   the next release. Does provide an upgrade path, but doesn't solve
   the probem immediately.

Matthias