Notes:
* This will not be presented if the verbosity is set to brief.
* At the present time, no filtering of obvious or default types is
  taking place. (Example: The default popup of an ARIA combo box is
  "listbox". Rather than filtering it out, Orca will present it.
* The information is being tacked on to the very end of presentation
  so it can be interrupted by users who don't find it meaningful.
* What gets spoken when is subject to change based on user feedback.

Note: This can be bypassed by adding the following lines to your
orca-customizations.py:

import orca.settings
orca.settings.presentLiveRegionFromInactiveTab = True

Alt+Tabbing into application windows is sometimes causing gnome-shell
to emit object:state-changed:focused events for an accessible with
the role of window. This is at least sometimes taking place after the
application window gains focus. Since no gnome-shell window seems to
be actually gaining focus, and since windows are expected to emit
window:activate events, these events appear safe to ignore. In addition,
failure to ignore them can cause Orca to load the gnome-shell script
incorrectly.

(cherry picked from commit ee69454f)

This reverts commit 5233b356.

It introduced unwanted chattiness.

When we get the selection-change on a parent of embedded children,
and the selection change spans multiple objects, we want to present
all the changes; not just update the cached selection.