Message4994

In distutils/util.py, the function `change_root' is aware of Jython but 
makes a rash assumption that Jython is always running on a POSIX pathed 
host system.

This is seen in the snippet where it merely strips off the first 
character of the pathname and believes that is sufficient to make the 
path relative. On NT pathed systems, this will merely remove the drive 
letter, leaving ":\jython" as the "relative" path, which it obviously is 
not.

The function `os.path.stripdrive' is documented that it is harmless to 
use on a POSIX pathed system, but essential for our needs on a Jython-
on-NT system.

I verified that with this patch applied, `bdist_dumb' on a Jython-on-
Linux system still behaves as it did before, and behaves correctly on 
Jython-on-NT.