Add clear all recents action to recents panel

Change-Id: I2243ebc83abc483e78b112900a653d7e61edc5ba
Fix - place Clear Recents button above the nav bar

Change-Id: Ie7059cd1f71bae28ff25f367221b7c7ba0131932
AppOps: track op persistence by name instead of id

On XML write, include the op name.  On XML read, map
the name back to op id (if it exists).

Persistent AppOp state now follows the op name instead
numeric id.  This allows upgrades between versions of
android that have different code<>name mappings.

Change-Id: Iffc02095b6838a34ff999f8db51c2c6739dd0db8
allow forcing HighEndGfx mode

people have already started fipping the lomRam prop to enable
transparent status bar, this will enable it with fewer
repercussions

Change-Id: Ied6de65276425fa1e7db0bf9da35f1932a355172