[Python-Dev] Python install layout and the PATH on win32

[VanL]

I heard back from Enthought on this part of the proposal. They could 
accommodate this change.

1) The layout for the python root directory for all platforms should be
as follows:

stdlib = {base/userbase}/lib/
platstdlib = {base/userbase}/lib/
purelib = {base/userbase}/lib/site-packages
platlib = {base/userbase}/lib/site-packages
include = {base/userbase}/include/python{py_version_short}
scripts = {base/userbase}/bin
data = {base/userbase}