Framework: Restore Keyguard-obsolete to AOSP state

Some of the CM features code got merged into the obsolete keyguard
code, revert to pure AOSP state.

Change-Id: I6980f9254b49cf1208dd1536f625951d804445ae
Port "Fix display of mobile status bar icon when using airplane mode"

Change-Id: Icb5b33008f97eaefd67bb4e5acd1e38bcf2dcb70
Improve tethering notification icons

Replaces the stock icons with the ones I submitted as part of
http://review.cyanogenmod.com/#/c/15930/ in CM9.

Change-Id: Iecfae9ad579c6c9ae06da0a08b61e9359a8a37b0
Remove GB alert drawable from reboot menu

Change-Id: I77cd3fabaed76c6cdd1ba051d628254c2f79974c