Check that the python interpreter can execute help.

def check_python_help(filename):
    """Check that the python interpreter can execute help."""
    try:
        proc = run_program(filename, ["-h"])
        output = to_text_string(proc.communicate()[0])
        valid = ("Options and arguments (and corresponding environment "
                 "variables)")
        if 'usage:' in output and valid in output:
            return True
        else:
            return False
    except:
        return False