git-p4.py: doesn't handle symlinks

My python-fu is weak and I don't have the time tonight to unravel it,
but in case somebody cares (or has a quick fix), it appears that the 
git-p4.py script deals with symlinks in p4 by checking in a textfile 
(to git) containing the name of the target of the symlink.

Of course there *shouldn't* be symlinks in the p4 depot I'm importing
from at all, but that's a different sort of problem.

Brian