Recents: Port "Development shortcut" (2/2)

This patch includes the equivalent of our Development Shortcuts in
CM11 recents. Recents is very different now and this is mostly a rewrite.

The semantics changed a bit as well. The current code already has special
developer behavior when long-pressing the app icon and that is also where
the developer shortcuts are hooked. If the app icon is long-pressed and
developer shortcuts are active, a menu will be shown with the several available
options.

Fixes CML-61

Change-Id: I391a360b3dd88e179c2315503d18125f8d0b3792
SystemServer: Move sensor init to a new thread.

Move Sensor init to a separate thread so that it doesn't block the
critical booting path.

Initializing Sensors in separate thread has been seen to improve boot
time on customer devices with low-tier / ult chipsets(less cpu cores)

Change-Id: I5c46a5805c04ffe551019b4683523e3bf70274a2