User management and switching

Broadcast intents that get sent out when users are added/removed/switched.

More work on generating user-specific information in package manager queries.
APIs to update user name and query a user by id.
Removed Package.mSetStopped and mSetEnabled, since they're not user specific.

User removal:
- Cleanup ActivityManager, PackageManager, WallpaperManager, AppWidgetService
  and AccountManager.
- Shutdown processes belonging to the user.

Don't show vibrate option in long-press power if there's no vibrator.

Lock the screen when switching users, to force unlocking.

Change-Id: Ib23a721cb75285eef5fd6ba8c7272462764038fa
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index d1e3642..3e57212 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -60,6 +60,9 @@
     <protected-broadcast android:name="android.intent.action.REBOOT" />
     <protected-broadcast android:name="android.intent.action.DOCK_EVENT" />
     <protected-broadcast android:name="android.intent.action.MASTER_CLEAR_NOTIFICATION" />
+    <protected-broadcast android:name="android.intent.action.USER_ADDED" />
+    <protected-broadcast android:name="android.intent.action.USER_REMOVED" />
+    <protected-broadcast android:name="android.intent.action.USER_SWITCHED" />
 
     <protected-broadcast android:name="android.app.action.ENTER_CAR_MODE" />
     <protected-broadcast android:name="android.app.action.EXIT_CAR_MODE" />