[1/2] Add network stats to status bar

Also includes
http://gerrit.aokp.co/#/c/13356/
http://gerrit.aokp.co/#/c/13360/

PS2:
Get the time delta between updates and use that to show
average bytes per second.

Change-Id: Ib06a713e6d93649ae8c8e5be5fd62c4f44a48416

PS3:
Code cleanup, change default text color and size to fit
AOKP and add ability to change text color.

PS4:
Fix up layout for cleaner spacing and add for tablets

PS8: Moved indicator before status icons

Change-Id: Ie3cdb038fecfe8cbb9b7a670c50dc7ebd22690e1

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/res/values/dimens_custom.xml
	packages/SystemUI/res/values/styles_custom.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBarTransitions.java

Conflicts:
	packages/SystemUI/res/values/slim_dimens.xml
	packages/SystemUI/res/values/styles.xml
Network stats: Improved codes

* Format speed text using Formatter.formatFileSize
* Set speed text to empty if speed below 1 KB
* Don't do unnecessary things if network stats is disabled
* Address appropriate task for each intent
* SettingsObserver should only observe settings part

Change-Id: I02f7bbb3f911569d2227e3df21e5c72456a157c4
Bring back the status bar activity indicators for mobile data and wifi

Google were nice enough to create xxhdpi drawables for us before removing them.

Reverts "Remove signal/wifi activity indicator icon overlays."

This reverts commit fcc901c10bffdfb9c6b31e676dec36b47d949979.

Change-Id: I7aa85f7c8442c45d17e42cac7823dfe93e3f24c1
Avoid layout passes when updating data activity indicators.

ImageView can optimize out layout passes if old and new drawable have
equal sizes. Take advantage of that by displaying a transparent drawable
with the same size as the in/out drawables when there's no activity
instead of clearing out the drawable in that case.

Change-Id: Iaaa556ffab3ed4be1da8016ed40d0a9c2efcde01