Heads up master switch (2/2)

Add an short explanation abaout how to enable Heads Up per app for those who don't like to read or serch in changelogs

Change-Id: I2f00ad71e564bc15c3904d295cfdccc4a4673996

Conflicts:
	res/values/cr_strings.xml
	res/xml/heads_up_settings.xml
Add more explanation in case of disable heads up through master switch

- Call ui and mms will stop receive heads up notifications automatically

Change-Id: Ie800b84e203d59cb922b82815f538cc28ec1c8e6
Settings: Heads Up background color && transparency [1/2]

Change-Id: I7a37f9d5a7c0e682b1f9670c3b839e3f063dc45c
PS12: squash dependency - heads up settings now under interface menu
PS: add ability to set custom heads up text color

Conflicts:
	res/values/cr_strings.xml
Merge remote-tracking branch 'crist/cm-11.0' into kitkat1

Signed-off-by: k2wl <kar2wlan@gmail.com>

Conflicts:
	res/values/cr_strings.xml

Change-Id: I1caab34f3745266a0bca6dd91a3d2bd25a24c34e