Support '--user' argument to distribute_setup.py
I'm currently putting together a description of how to set up a Python stack where all the packages except the standard library are stored in the user directory. The setup instructions for distribute are more complicated than they need to be because distribute_setup.py doesn't pass the "--user" argument through to the underlying "setup.py install" call.
(This was previously mentioned as an aside in
#30, but that issue was closed when the main problem was overtaken by events).