``InsetIndicator`` artist
~~~~~~~~~~~~~~~~~~~~~~~~~

`~.Axes.indicate_inset` and `~.Axes.indicate_inset_zoom` now return an instance
of `~matplotlib.inset.InsetIndicator`.  Use the
`~matplotlib.inset.InsetIndicator.rectangle` and
`~matplotlib.inset.InsetIndicator.connectors` properties of this artist to
access the objects that were previously returned directly.
