--clear option doesn't remove previous python version

[anatoly techtonik]

Latest 1.3.3dev changes environment, but refuses to overwrite ENV/bin/python symlink even with --clear option. The original virtual-python.py does this even without clear and it seem more logical.

$ python2.4 virtualenv.py --clear ~/inst
Deleting tree /home/user/inst/lib/python2.4
Not deleting /home/user/inst/bin
New python executable in /home/user/inst/bin/python2.4
Not overwriting existing python script /home/user/inst/bin/python (you must use /home/user/inst/bin/python2.4)
Installing setuptools.............................done.
$

[Carl Meyer (carljm)]

Migrated to https://github.com/pypa/virtualenv/issues/2