FW: Halo
Credit: Paranoid Android

Change-Id: Ic47c74e4b8735b2461a1d54be3ba8cdd30c3d7d6
HALO cleanup

hdpi and mdpi drawables were inconsistent, if you plan to use HALO on
lower res devices you must reproduce them.

Change-Id: I2746837bacd60c3079ace4c7523a68b8cd415f5f

Conflicts:
	core/java/com/android/internal/widget/ActionBarView.java
HALO: new drawables for hdpi and mdpi

- scaled down the xhdpi drawables properly for hdpi and mdpi
- removed some old and unused halo pngs

Conflicts:
	packages/SystemUI/res/drawable-mdpi/ic_notify_halo_normal.png
	packages/SystemUI/res/drawable-mdpi/ic_notify_halo_pressed.png

Change-Id: I90e8052453b6f4cb62657bb5c59dc2382088271e
HALO: Option to pause the underlying app (1/2)
- adds an option to pause the active app when using HALO
- this is enabled by default for devices with low memory
- (currently: <640MB RAM available to the kernel)

Change-Id: I7fdf02ec1dc2da0de35925dbdd0e06ad4a37719a
Credit: tonyp
Reworked transparent layer
When a halo'ed window is opened, the transparent layer will be always visible. It will manage the background dim.
This fixes some apps dimming its sandboxed processes (like chrome).

LayerActivity manages its own lifecycle. When it's focused after paused it finishes itself.

System processes (identified by "android" pkg in SystemUI and system uid in Activity) don't use the layer and still use their own background. This
has been kept this way to not interfere with their activity.

Change-Id: Ic395db4b9c31f6b839d86c7bd9fd8507c7905241
Credit: Beerbong
Fix little derp causing visual bug
To reproduce, disable halo, and press "clear all notifications" button

Change-Id: Ie5d4ebdd65224e114fd9a5c9aeec878a3e42f029
Credit: Jesus David
Halo: Add master switch to disable Halo (1/2)
-Port master switch from @Der-Schubi.
-Fixed Halo not showed at first notifiction pulldown.

Change-Id: I07ee32b66c1e8c4f832f436bf8c38925093fcaf4
Credit: Der-Schubi