RFC: another Python refcounting fix

[Tom Tromey]

>>>>> "Tom" == Tom Tromey <tromey@redhat.com> writes:

Tom> I had a couple more refcounting fixes on my Python checker branch.
Tom> Here's the first one.  finish_python_initialization does not decref
Tom> 'pythondir' along all the exit paths.

Tom> Built and regtested on x86-64 Fedora 18.

Tom> 	* python/python.c (finish_python_initialization): Decref
Tom> 	'pythondir' on failure path as well.

I'm checking this in now.

Tom