actions.py translation. Using mapping rather than tuple for args. Format an error message in handleCollision using named tokens '%(props)s' rather than printf positional format specifier %s. Regenerate roundup.pot and update all .po files to use named tokens in their trnslations. Test handleCollision as well.

try:
    # Python 3+.
    from xmlrpc import client, server
    server.SimpleXMLRPCDispatcher
except (ImportError, AttributeError):
    # Python 2.
    import xmlrpclib as client  # noqa: F401
    import SimpleXMLRPCServer as server