endSessionDialog: Factor out _updateDescription from _updateContent

_startTimer adds a tweener to implement the description countdown, which
updates the entire content on each iteration, including the icon. This
causes a significant impact on performance, especially when accessibility
is enabled, as it causes a flood of AtkObject:state-change:showing events.
As the countdown only affects the description, factor out _updateDescription
and use it in _startTimer, and only do a full update of all contents when
necessary.

https://bugzilla.gnome.org/show_bug.cgi?id=674210
popupMenu: bypass changeSignal callback if action is already handled

https://bugzilla.gnome.org/show_bug.cgi?id=676447
popupMenu: do not overflow the currentItems

Do not overflow currentItems array. If the Menu section is filled
via model items-changed callback the position in the model passed to
the RemoteMenu _modelChanged can be a to be added asynchronously
action-added. Thus the item does not yet exists in the currentItems.

https://bugzilla.gnome.org/show_bug.cgi?id=676447
css: add a 'hidden' style class

Used for elements that are not supposed to be shown.

https://bugzilla.gnome.org/show_bug.cgi?id=675341
a11y: do not expose a label text if 'hidden' style class is used

https://bugzilla.gnome.org/show_bug.cgi?id=675341
Bump version to 3.5.2

Update NEWS
Require Mutter 3.5.2
main: Adapt to new plugin API
network: Remove old API

The underscored properties were removed a while ago.

https://bugzilla.gnome.org/show_bug.cgi?id=677515
calendar: Adapt to Evolution-Data-Server API changes.

Adapt the calendar-server to some major API changes in E-D-S 3.5.3.

More details about the breakage:
http://mbarnes.livejournal.com/4631.html

https://bugzilla.gnome.org/show_bug.cgi?id=677402
LayoutManager: Add primary-fullscreen-changed signal

Add a signal to the LayoutManager which gets emitted once the primary monitor
enters or leaves the fullscreen state.

https://bugzilla.gnome.org/show_bug.cgi?id=677590
messageTray: Don't show non urgent notifications while in fullscreen

Don't show non urgent notifications when the primary monitor
is in fullscreen (user watching a movie, having a presentation,
playing a game ...).

Once the user leaves fullscreen show the messagetray so that the user don't
miss any notification (same as in "back from idle").

https://bugzilla.gnome.org/show_bug.cgi?id=677590
calendar-server: Remove left-over include

GConf-free at last! GConf-free at last!
Updated Slovenian translation
modalDialog: show dialogs on monitor with the mouse pointer

Show the dialog on the monitor containing the pointer, rather than
the monitor with active focused window. This brings it inline with
the behaviour seen when launching applications.

Remove the focusMonitor/focusIndex from LayoutManager. These
properties were only used by the modal dialogs. Remove them since
they are not being used elsewhere.

https://bugzilla.gnome.org/show_bug.cgi?id=642591
Updated Russian translation
Updated Greek translation
data: Actually substitute @GETTEXT_PACKAGE@ in schema files

https://bugzilla.gnome.org/show_bug.cgi?id=677497
extensionSystem: Initialize the HTTP session after parse time

We really shouldn't be creating GObjects while we're still parsing other
files for performance and clarity reasons.
Revert "extensionSystem: Initialize the HTTP session after parse time"

This reverts commit df5298d59c2c7b79c7477ecd1a9cf2dfa25e3b59.
extensionSystem: Initialize the HTTP session after parse time

We really shouldn't be creating GObjects while we're still parsing other
files for performance and clarity reasons.

https://bugzilla.gnome.org/show_bug.cgi?id=677586