DocumentsUI: Add a standalone File Manager

This commit adds a standalone mode to the DocumentsUI, to let
it act as a file manager/explorer.
You can browse your storage contents, open files, and delete them,
as well as do everything that the DocumentsUI can do (ie. sort
by name/size/type, list and grid view, recents, search, ...).

This gives us a consistent file browsing UX accross all apps
that uses the new documents API.

Change-Id: If73a3c100f010bdb766c843976d4fd3573ea805c
[1/2] Base: Lockscreen Notifications (All Patches included)
GlobalActions: Set the initial status of airplane mode toggle

Actually, the initial status of airplane mode toggle is set to false
when the power menu dialog is initialized.
This causes an issue if you set airplane mode and then reboot.
After the reboot, the dialog displays the wrong airplane mode status,
eg. "Airplane mode is not active", and if you toggle that option, a wrong
intent is sent again to put ON the airplane mode, instead of OFF, the
toggle (that is in transition state) will be set disabled.

This commit fixes this issue.

Change-Id: Id30355c1e090355645c437086c79ab59093c27a8
[1/2] Base: Option to enable Notification Light when screen is on

This makes it possible to let the Notification LED flash even when the screen is on

Change-Id: I58be9646cdc84d4765342a5ab45b4641c3d5daba

Conflicts:
	core/java/android/provider/Settings.java
	services/java/com/android/server/NotificationManagerService.java
Smoother Upload and Download Animation

Change-Id: I6e6409cc85ad951019dbac10156d4aed92f4c5bc
Show live wallpapers in the recents view on high-end devices

Change-Id: Iefbf4f292b6a9bfdb516f154cc2976db2ba86cde
Base: Power Menu Config & Immersive Mode [1/2]
Bring back the status bar activity indicators for mobile data and wifi

* adds a setting for this as well as reverting the following commit:

Reverts "Remove signal/wifi activity indicator icon overlays."

This reverts commit fcc901c10bffdfb9c6b31e676dec36b47d949979.

Change-Id: I7aa85f7c8442c45d17e42cac7823dfe93e3f24c1
Update immersive confirmation.

1. Disable panic mechanism for expanded desktop.
2. Separate confirmation for each expanded desktop style.
3. Add new layout for the case when navigation
   bar is hidden but statusbar is visible.

Change-Id: I5914d655bd5f9315ac4cc6fc7d70cc4ee45bb7b2

Conflicts:
	core/res/res/values/purity_strings.xml
WifiState: Don't aquire transitionwakelock in airplane mode

NetworkTransitionWakelock is for transition from Wifi to mobile.
It will cause device no sleep for 60s. There is no need to acquire
it in airplane mode.

Change-Id: I1487dc4787948d09e482f22e88d01768b54964da
Fix for notification light settings