ShellContactSystem: fix GeeMapIterator leak

https://bugzilla.gnome.org/show_bug.cgi?id=678079
shell-util: fix GFile leak

https://bugzilla.gnome.org/show_bug.cgi?id=678079
ShellContactSystem: fix GSList leak

https://bugzilla.gnome.org/show_bug.cgi?id=678079
ShellContactSystem: fix GSList of utf8 leak

https://bugzilla.gnome.org/show_bug.cgi?id=678079
st-texture-cache: fix GtkIconInfo leak

https://bugzilla.gnome.org/show_bug.cgi?id=678079
telepathyClient: decline dispatch op when approving unsupported channel type

It shouldn't happen in theory but best to be safe than sorry.

https://bugzilla.gnome.org/show_bug.cgi?id=677457
telepathyClient: ignore invalidated channels

There is a race if a channel is invalidated during its preparation: the
'invalidated' signal is already emitted so the Shell will never notice.
We fix this by simply checking if the channel is already invalidated when
receiving it from telepathy-glib.

In the approving case, we reject the full ChannelDispatchOperation as we only
support approving one channel at the time.

https://bugzilla.gnome.org/show_bug.cgi?id=677457
Depend on gjs 1.33.2

Shell uses the 'format' module which has been introduced in gjs 1.33.2.

https://bugzilla.gnome.org/show_bug.cgi?id=678396
shell-app: Update app menu if necessary

Currently we assume that GTK_UNIQUE_BUS_NAME is shared between all
windows of an application. This assumption does not hold true for
applications that specify G_APPLICATION_NON_UNIQUE, so make sure
to update the menu as necessary.

https://bugzilla.gnome.org/show_bug.cgi?id=676238
Enable the Screen Reader menu item

https://bugzilla.gnome.org/show_bug.cgi?id=663256
workspace: Remove unused method

This one hasn't been used for quite a while now ...

https://bugzilla.gnome.org/show_bug.cgi?id=678416
workspace: Minor cleanup

_hideAllOverlays() has only been used in a single place for quite
some time now, so move its code into the caller and save a loop.

https://bugzilla.gnome.org/show_bug.cgi?id=678416
Disable unredirection when a modal operation is active

When the shell takes control of the screen (for example to show
a modal dialog or to lock the screen), it must reestablish itself
on top of the stack, and in particular restore any unredirected
window so that it is composited below the Shell UI.

Reviewed-By: drago01 in IRC.
Login dialog: update for GDM port to GDBus

libgdmgreeter changed interface slightly due to the port to GDBus.
Update for that.

https://bugzilla.gnome.org/show_bug.cgi?id=676401
screenShield: add initial functionality

We are replacing the gnome-screensaver module with with a screen shield
that is part of gnome-shell.

This patch fades out the screen on idle and shows a shield with a background
image when there is activity again. The shield can be removed with a key or
button press.
lightbox: make sure this.shown set to false when start showing
Add UnlockDialog for unlocking the screen shield

When the screenshield is deactivated, instead of going back to the
session immediately, prompt the user for authentication.
This essentially reinstates what used to be provided by gnome-screensaver.
ScreenShield: improve locking/modal policy

Ensure that the lightbox is above everything (including the screenlock
itself) when fading in - this allows for fading while showing the
unlock dialog. Also, don't pushModal again when already locked, or
we won't get out of it.
Modal stack: fix handling of destroyed actors

Destroyed modal actors should be completely removed from the modal
stack automatically, including leaving modality if needed.
This allows for destroying modal dialogs without calling close().
ScreenShield: reset isLocked flag when unlocking

Otherwise further locking will get us confused and cause "incorrect
pop" JS errors (as well as keeping the shell modal forever).