power: Don't leak notifications

https://bugzilla.gnome.org/show_bug.cgi?id=673978
power: Avoid duplicate translations

It confuses our tools if we have the same msgid both in
gettext() and ngettext(), so be a bit more clever here.
Bonus: save 40 lines of code.

https://bugzilla.gnome.org/show_bug.cgi?id=669732
Don't pass NULL where a dialog is expected

...it leads to crash. Seen in
https://bugzilla.redhat.com/show_bug.cgi?id=831666

https://bugzilla.gnome.org/show_bug.cgi?id=678133
a11y-keyboard: point to an existing help page

The overall a11y help page might not be the best fit here,
but it beats a nonresolving URL.

https://bugzilla.gnome.org/show_bug.cgi?id=678198
Updated Slovak translation
mouse: Fix touchpad/mouse settings not getting updated

If one of the devices was ignored, we would ignore all the
subsequent devices.
power: fix DBus path of gnome-screensaver

The right path for both gnome-screensaver and gnome-shell is
/org/gnome/ScreenSaver. It was never noticed because the proxy
is created without properties and there is no callback in the
method calls.

https://bugzilla.gnome.org/show_bug.cgi?id=682007
wacom: Upgrade the libwacom dependency

to version 0.6 as previous version would trigger
bug 672917

https://bugzilla.gnome.org/show_bug.cgi?id=672917

Conflicts:
	configure.ac
wacom: Fix warning caused by new libwacom API
media-keys: Handle "toggle brightness" events

Toggle would lower the brightness, as:
KEYBOARD_BRIGHTNESS_TOGGLE_KEY != KEYBOARD_BRIGHTNESS_TOGGLE_KEY

https://bugzilla.gnome.org/show_bug.cgi?id=682564
Updated kn translation
Updated kn translation
housekeeping: Don't leak notification objects

https://bugzilla.gnome.org/show_bug.cgi?id=679177
housekeeping: Don't crash on exit

If a notification popup was shown, and then dismissed, notification
wouldn't have been reset, and we would crash on exit trying to
dismiss it.

https://bugzilla.redhat.com/show_bug.cgi?id=859383
https://bugzilla.gnome.org/show_bug.cgi?id=684548
housekeeping: Fix typo
housekeeping: Really don't crash on exit

Function arg "notification" shadowed global var "notification"

https://bugzilla.gnome.org/show_bug.cgi?id=685133
housekeeping: Fix test crashed on notification

https://bugzilla.gnome.org/show_bug.cgi?id=685133
power: Fix possible crashers reusing set GError

When setting the panel's backlight can't be turned off for example,
switching off the keyboard's backlight will fail as well, as the
error will be invalid for use.

https://bugzilla.gnome.org/show_bug.cgi?id=686468
sound: Remove use of never-defined HAVE_PULSE

HAVE_PULSE was never defined so the sound plugin was
completely unused. This would cause theme changes to not be
noticed.

Spotted by Lionel Landwerlin <llandwerlin@gmail.com>

https://bugzilla.gnome.org/show_bug.cgi?id=674871
keyboard: Prevent potential infinite loop

XKB would notify us in the same way if the lockedMods
changed because of a programmatic, or a physical/human change.

This causes us changing the Num-Lock state generating another
event on top of the one we just processed, and might cause
infinite loops and 100% CPU usage.

Instead, we now only apply the settings:
- on startup
- when remember-num-lock is changed to true

https://bugzilla.gnome.org/show_bug.cgi?id=679151

Conflicts:
	plugins/keyboard/gsd-keyboard-manager.c