Settings : Add hooks for device specific features

Add support for :

Devices with bluetooth input peripherals
Devices with screen gesture support
Devices with a back touchpad

Change-Id: Iabad460a6d1b0d8bf2e84ace92dea1f6901fb4d0
Revert "Settings: Fix aapt warnings (translation)"

This reverts commit 9c8a03f2714b09d43ee94c64f08116abf48c102e.
Merge "Settings : Add hooks for device specific features" into cm-10.2
Merge remote-tracking branch 'cm/cm-10.2' into cm-10.2