[1/2] Speed up booting on multicore devices.

1. Add multithreading support to Installer/installd.
2. Parallelize package scanning.
3. Parallelize boot dexopt.

Change-Id: Id42b2bf4a737f93f9ecd9b5819344adbb735f0fb

Conflicts:
	services/java/com/android/server/pm/PackageManagerService.java
PackageManager: Fix concurrent access to shared state

Stop multiple threads from all calling add on the same HashMap.

Cleanup the use of a boolean flag by removing concurrent writes
to it.

Change-Id: I8d61fe7294dcb67ee7d0d7de88d90d2051c310e6
Parallel shutdown

Decrease shutdown time by doing some shutdown tasks in parallel.

There are two threads executing during the shut down: the ShutdownThread
and a separate thread for the radio shutdown. However, the execution is
done in serial, as the ShutdownThread immediately joins on the radio
thread.

This commit will move the shutdown of the radio to the beginning of
shutdown and execute it in parallel to the shutdown of the rest of the
system.

The flow of the two threads during shutdown is now:

Radio Thread
  * Start shutdown of the radio
  * Wait for radio off or time out
  * Notify that the radio is done
ShutdownThread
  * Broadcast ACTION_SHUTDOWN as a parallel broadcast. (The receivers
    will get as much time to handle onReceive as it takes execute the
    rest of the tasks in the shut down flow. If they are not done in
    that time, we don't care.)
  * Shutdown ActivityManager
  * Shutdown MountService
  * Wait for MountService and radio to notify done
  * Vibrate
  * Low level shutdown

Change-Id: Ifdd8a9c75337fd9d00148a0d2b9917e10fa60634

Conflicts:
	services/java/com/android/server/power/ShutdownThread.java
Improve scrolling cache

Scrolling cache helps make short scrolls/flings smooth but will
cause stutter when long flings are made. This patch disables
scrolling cache when long flings are made.

This patch also fixes a related bug where scrolling cache will
not be enabled properly when transitioning from flinging to scrolling.

Patch Set 2: Calculate threshold based on maximum velocity (Sang Tae Park)

Change-Id: I1fdbaad92263c9f983a32900e74eba1f0367902b