[1.9.x] Corrected a few typos in Signal.send() docstring.

        Send signal from sender to all connected receivers.

        If any receiver raises an error, the error propagates back through send,

        terminating the dispatch loop, so it is quite possible to not have all

        receivers called if a raises an error.

        terminating the dispatch loop. So it's possible that all receivers

        won't be called if an error is raised.

        Arguments:

            sender

                The sender of the signal Either a specific object or None.

                The sender of the signal. Either a specific object or None.

            named

                Named arguments which will be passed to receivers.