Add a special background to use for performance testing

Performance testing was producing inconsistent values at different
times in the day since the GNOME default background is animated and
sometimes has a single layer, and sometimes two blended layers.

So we have consistent numbers, install a simple animated background
with GNOME Shell that has 40-year long transition ending in 2030,a
and set an environment variable in gnome-shell-perf-tool so that the
background is override with that background. (The background depends
on files installed by gnome-backgrounds; we assume that the person
running performance tests is doing so within the scope of a full
GNOME install.)

https://bugzilla.gnome.org/show_bug.cgi?id=734610
altTab: Fix WindowSwitcherPopup

The "backwards" parameter needs to be dropped here as well.
perf-tool: Remove dead code
Updated Traditional Chinese translation(Hong Kong and Taiwan)
popupMenu: Remove unused function
search: add support for default disabled search providers

Search providers that should be disabled by default come with
a DefaultDisabled=true key in their keyfile, and are enabled
with the "enabled" whitelist, not with the "disabled" blacklist.

https://bugzilla.gnome.org/show_bug.cgi?id=734110
SearchEntry: replace the ID with a style class

This way extension authors can create entries that look and feel
like the overview search entry.

https://bugzilla.gnome.org/show_bug.cgi?id=733813
PortalHelper: fix portals that don't redirect properly

We assumed that either a portal would give us a target URI, or we
would eventually reach the URI of our choice (which is http://www.gnome.org)

This is not always the case: even after a successful login we may
stay in a confirmation page, so make sure that every time we see a
redirect we trigger a connectivity check (or queue one for when
the user closes the window)

https://bugzilla.gnome.org/show_bug.cgi?id=733848
TelepathyClient: fix history trimming

We need to put the actual actors in the history, not just the labels,
otherwise all emptyLine (which are not messages but are not empty
either) and all lines with a timestamp will get stuck in the scrollback.

https://bugzilla.gnome.org/show_bug.cgi?id=733899
dateMenu: Try to use the default calendar application

Commit 14ceb10555699 changed the "Open Calendar" item to open the
"recommended" calendar application rather than the default one to
avoid problems with MIME subclassing (namely falling back to the
default text editor when no calendar app is installed).
With this change however, the application launched does no longer
necessarily match the one configured in Settings, which is unexpected.
To avoid both problems, use the default calendar application again,
but only if it is in the list of recommended applications.

https://bugzilla.gnome.org/show_bug.cgi?id=722333
search: Fix visibility of "more" icon

Since commit 19749bb37fda75b2b, the icon is always visible - ooops.
runDialog: catch the case where no completion is available

Just return null, instead of failing with an exception later trying to
call substr() on null.

https://bugzilla.gnome.org/show_bug.cgi?id=735062
search: Fix custom drag actor source

The existing code broke when commit 792b963bda8c changed the custom
result actor hook to return an object instead of an actor - stop
trying to go through a _delegate to make it work again.
tweener: Also consider delay when disabling animations

'time' is not the only timing parameter for tweens, in order to
really disable animations, we need to override 'delay' as well.
iconGrid: Move code around a bit

The scale passed to _updateChildrenScale is exclusively computed from
properties, so it can be moved into the function itself - as the scale
now becomes a mere detail, rename to a more appropriate _updateIconSizes
at the same time.
appDisplay: Animate folder view items

Add a new animation  to folder view based on designers mockups that
emulates pulsating icons.
The code on iconGrid is though to work well for the upcoming patches to
animate AllView and FrequentView.

https://bugzilla.gnome.org/show_bug.cgi?id=734726
viewSelector: Allow different animation types

Make viewSelector able to manage different kind of animations for pages.
This is necessary for the upcoming patch to animate AllView and
FrequentView.

https://bugzilla.gnome.org/show_bug.cgi?id=734726
appDisplay: Animate AllView and FrequentView

Following design decision, we want to animate AllView and FrequentView
when opening and closing with a swarm spring form.

This involves a few changes needed to allow that, since from some time
now, we are animating page changes in viewSelector, using only a fade
transition. However now we want to let appDisplay and iconGrid apply its
own animation.

For that we special case the change to and from apps page on
viewSelector to let appDisplay to animate its own items, using and API
on appDisplay which at the same time uses an API on iconGrid.

However animating the icons in iconGrid involves a few challenges due to
the current need of scaling icons on iconGrid on a call which uses
BEFORE_REDRAW.  We need to call animate() after the icons are already
scaled, that means however, calling after a BEFORE_REDRAW, so that
means, we have to call animate() in a call using BEFORE_REDRAW which
call a function using BEFORE_REDRAW as well, so we wait two frames to
make sure icons are scaled correctly.

Thanks Florian Mullner for the debugging work

https://bugzilla.gnome.org/show_bug.cgi?id=734726
appDisplay: Animate indicators out

Given that we animate indicator in, it makes sense to animate them out
as well.

https://bugzilla.gnome.org/show_bug.cgi?id=734726
Search: cleanup unused code

https://bugzilla.gnome.org/show_bug.cgi?id=734726