scroll-view-fade: Fix [vh]fade_offset property getters

The two were mixed up all along, and nobody noticed ...

https://bugzilla.gnome.org/show_bug.cgi?id=694125
appDisplay: Fix _ensureIconVisible()

The fade effect was renamed a while ago, but we missed to update
the use in _ensureIconVisible().

https://bugzilla.gnome.org/show_bug.cgi?id=694125
loginDialog: fix cancel from "Not Listed?"

Since commit 1ae0fadbf483128e27565baba6e8684bc5defca2 we
no longer start a PAM conversation as soon as the user clicks
the "Not Listed?" button.  Instead we defer starting the PAM
conversation until the user types their username.

Unfortunately, the cancel button resets the dialog back to the
user list indrectly by cancelling the current PAM conversation.

This means if the user hasn't yet entered thier username then
the cancel button doesn't work.

This commit performs a direct dialog reset in the case the
PAM conversation hasn't been started yet.

https://bugzilla.gnome.org/show_bug.cgi?id=693756
loginDialog: don't try to stop work spinner if it's already gone

This can happen if the dialog gets reset at the wrong moment.

https://bugzilla.gnome.org/show_bug.cgi?id=693757
dash: don't react to window drags

Instead, make the actor half-opaque in that case.

https://bugzilla.gnome.org/show_bug.cgi?id=686984
overviewControls: use Params for SlidingControl constructor

https://bugzilla.gnome.org/show_bug.cgi?id=686984
build: Bump gnome-desktop requirement to 3.7.90
userMenu: Use single quotes for non translateable strings

Coding style cleanup ...
l10n: Updated Italian translation
polKitAgent: Don't crash when we cannot enable/disable the auth agent

This makes it easier to run with jhbuild.

https://bugzilla.gnome.org/show_bug.cgi?id=687556
theme: add some transparency to the menu backgrounds

They look too hard with a fully opaque black background. A small
bit of transparency will give a softer appearance without impairing
readability.

https://bugzilla.gnome.org/show_bug.cgi?id=694202
Updated POTFILES.in
AccessibilityMenu: hide when not needed

Tie the menu visibility to having at least one a11y feature enabled.

https://bugzilla.gnome.org/show_bug.cgi?id=681528
appDisplay: Remove categories

We will eventually display some categories as app folders, but the
existing code doesn't help with the implementation, so remove it.

https://bugzilla.gnome.org/show_bug.cgi?id=694192
appDisplay: Merge AppIcon and AppWellIcon

AppIcon is just a tiny wrapper around BaseIcon, which does not add
anything over using BaseIcon directly, so merge its code with
AppWellIcon. As the concept of the "app well" has not been used
since well before 3.0, use AppIcon as name for the merged class.

https://bugzilla.gnome.org/show_bug.cgi?id=694192
appDisplay: Merge AllAppDisplay and ViewByCategories

With categories removed, the separation between AllAppDisplay and
ViewByCategories no longer makes sense. Also use this opportunity
to rename the outdated AllAppDisplay to AppDisplay; it will
eventually be used to manage different views.

https://bugzilla.gnome.org/show_bug.cgi?id=694192
appDisplay: Remove unused variables

https://bugzilla.gnome.org/show_bug.cgi?id=694192
messageTray: Move makeCloseButton() into Util

The function is useful for other modules as well, so move it to a
more generic place.

https://bugzilla.gnome.org/show_bug.cgi?id=694192
appDisplay: Make _loadCategory() a utility function

When we bring back categories as folders, this method will be
useful outside of AppDisplay.

https://bugzilla.gnome.org/show_bug.cgi?id=694192
appDisplay: Set a maximum column number

In particular on widescreen monitors, the number of items in a row
can be overwhelming, so limit the number of columns and center the
view.

https://bugzilla.gnome.org/show_bug.cgi?id=694192