tests/readlink.py

shelve: drop pickle usage

Pickle was used to the `shelvedstate` file. However the content of the file is
very simple and we can handle serialisation ourself. Not using pickle is a net
win.

Note incrementing the format version as no releases have been done so far.

#!/usr/bin/env python

import errno, os, sys

for f in sys.argv[1:]:
    try:
        print f, '->', os.readlink(f)
    except OSError, err:
        if err.errno != errno.EINVAL:
            raise
        print f, 'not a symlink'

sys.exit(0)