[1.9.x] Fixed #26493 -- Documented how built-in signals are sent.

Signals

=======

A list of all the signals that Django sends.

A list of all the signals that Django sends. All built-in signals are sent

using the :meth:`~django.dispatch.Signal.send` method.

.. seealso::

.. method:: Signal.send(sender, **kwargs)

.. method:: Signal.send_robust(sender, **kwargs)

To send a signal, call either :meth:`Signal.send` or :meth:`Signal.send_robust`.

You must provide the ``sender`` argument (which is a class most of the time),

and may provide as many other keyword arguments as you like.

To send a signal, call either :meth:`Signal.send` (all built-in signals use

this) or :meth:`Signal.send_robust`. You must provide the ``sender`` argument

(which is a class most of the time) and may provide as many other keyword

arguments as you like.

For example, here's how sending our ``pizza_done`` signal might look::