Improve scrolling cache

Scrolling cache helps make short scrolls/flings smooth but will
cause stutter when long flings are made. This patch disables
scrolling cache when long flings are made.

This patch also fixes a related bug where scrolling cache will
not be enabled properly when transitioning from flinging to scrolling.

Patch Set 2: Calculate threshold based on maximum velocity (Sang Tae Park)

Credits: Pawit Pornkitprasan

Change-Id: Iad52a35120212c871ffd35df6184aeb678ee44aa
Bring Forward LTE Checks to fix Invalid Signal

In low LTE, ASU level shows as 99 (invalid)

Add some checks to get correct value.

Original Credit: Shareef Ali

PS2: Fix erroneous space

Change-Id: I5c2bd722655b6c4009119cba61e0a169adb3d7d4
Add battery level text to status bar (1/2)

1. Add TextView to display battery level percentage next to the battery
icon.
2. Remove support for displaying battery percentage on the actual
battery icon itself.
3. Also respect view on lockscreen and opened notification drawer.

Change-Id: Iab6228f5316908961c8647773bd3c8655df29679

Conflicts:
	packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
	packages/SystemUI/src/com/android/systemui/BatteryMeterView.java