Allow creating custom dialogs in DialogPreference.

This allows creating non-AlertDialogs while still using the click and
state handling of DialogPreference.

Change-Id: I54fd7d6d6b9f6a49fef1ae95e0178838b3edfa56
Notification LED Control (1/2).

[Original writen at CyanogenMod by David Van Tonder (DvTonder <david.vantonder@gmail.com>).]

* Make led color customizable.
* Global and per-app settings.
* Default led color is white.
* The option category replace old stock on/off checkbox.
* Remove useless code from display settings, the feature has its own java files.
* The java files in settings are stored into its own com/android/settings/notificationligh folder.
* Credits into code comments of each specific java file.

PS2/3/4:

* Fix code derps.
* Forget to define a method.
* Remove wrongly added code.

PS5/6:

* Move entries to pa_symbols and pa_config.
* Update description.

PS7:

* Use ArrayMap instead of HashMap (more memory efficient).
* Remove observer for medium battery level.

PS8:

* Correctly import ArrayMap.
* Didn't updated creating of ArrayMaps.

PS9/10:

* Fix defaults.
* Enable battery led.
* Update description.

PS11/12:

* Ditch battery led option.
* Update commit description.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

Change-Id: I34654992e0225c32413e6cbe9f0ca18c1729a186