add "Turn Wi-Fi off" action to the "open networks available" notification

Signed-off-by: Roman Birg <romanbirg@gmail.com>

Conflicts:
	core/res/res/values/strings.xml
	services/java/com/android/server/WifiService.java

PS2: Adapt to 4.3 changes
PS3: Adapt more to 4.3

Change-Id: Idaed26320a2ff2e6ada448fa6deb95a76d2b86d2
Moved custom string

Moved custom string from string.xml to custom_strings.xml. Inconsistency from previous am.
wifi: Allow Settings to retrieve country code

This makes getCountryCode behave like getFrequencyBand

This allows Settings to get/set country code like
it can for frequency band.

Conflicts:
	wifi/java/android/net/wifi/WifiStateMachine.java

Change-Id: Id9f00d3a678642c6c142fd1511af820d729507a7