Keyguard: more consistency with the new lockscreen wallpaper

* In the case when the screen was off and setCustomDrawable()
was being called, and the use wallpaper is null, then we could be
setting the color filter on a null drawable.

* Fix logic when old custom background was null and the new one is also
null (but could be the user one) and the func was being returned, thus not
clearing out the current media album art.

* Move resetting the shouldShowWallpaper() flag to the show() method
so it is not being called every time the screen is turned on.

* Fix user image not showing up on first boot if it exists

Change-Id: I567c2ec8920df627835defb822c2ea25be7b3cab
Signed-off-by: Roman Birg <roman@cyngn.com>

Conflicts:
	packages/Keyguard/src/com/android/keyguard/KeyguardViewManager.java
Lockscreen: Fix SystemUI crash on initial selection of Custom Background.

Change-Id: I8df4984f4b90d211baa888d380a95fc00a85d1ad

Conflicts:
	packages/Keyguard/src/com/android/keyguard/KeyguardViewManager.java

Conflicts:
	packages/Keyguard/src/com/android/keyguard/KeyguardViewManager.java
Add wallpaper pickers to seperate package [1/2]

Currently wallpaper pickers were part of the various launchers
and we were relying on Trebuchet's to add code for including
wallpapers from themes.  If Trebuchet is removed then this
functionality is lost.  This package is already included in all
builds so making the picker available here removes the dependency
on a specific launcher.

Trebuchet still contains a picker which should probably be removed
and make use of this package instead.

Change-Id: Ie42ae0e01f951a8293d13d6c8a73fde0dea6682b

Conflicts:
	packages/WallpaperCropper/src/com/android/wallpapercropper/WallpaperCropActivity.java
Lockscreen wallpaper for themes

Change-Id: If77b97301c5bfebd94b193fe9a54e676e678d3ed
fix for the last commit

Change-Id: Id25df0bcb5e2a66fb961737bbb94506a5f71a17d