Settings: Don't crash if we pause too quickly

Notifier is unregistered in every case in pause.
However, if you close the Settings app too quick, the notifier
might not be registered at all, causing an IllegalArgumentException
during the unregistering.

Change-Id: I54141cbfc91d08c28ef524f4155b673ae8dee90e
Status bar brightness control

+ added some fixes to original implementation (thanks mostly cm for that)
+ add multiuser support

Change-Id: I108086b07dea9cc6d59bfbdd9652b3aa33dcfe74

Conflicts:
	res/xml/additional_settings.xml
	src/com/android/settings/AOSPAL/AdditionalSettings.java
Add OmniSwitch to Dirty Tweaks

Change-Id: Id23d0482f4b40d0adaa23685afaceeddfa27370f

Conflicts:
	res/values/custom_strings.xml
	res/xml/dirtytweaks.xml