tests/readlink.py

Fix how setup.py identifies the Mercurial version.

There is a problem with setup.py where it will not identify the Mercurial
version properly when not being ran in within a repository even if
mercurial/__version__.py exists.

To fix, use mercurial.__version__.version when available before defaulting
to "unknown".  (Using mercurial.util.version() is not an option due to a
dependency issue where osutil can be referenced before it is built.)

#!/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)