core: Add support for Luxembourgish

Change-Id: Idd65417a08c5035a75e0d33617dc28c88757a293
Do not show Home behind full screen activity

When ensureActivitiesVisibleLocked goes through foreground activity
stack and reaches non-fullscreen activity, it sets showHomeBehindStack
variable to true.

If there is a fullscreen activity behind, showHomeBehindStack remains
unchanged, which causes Home application to be displayed anyway.
In this case user will see a fullscreen activity and Home activity
simultaneously.

To fix the issue we set showHomeBehindStack to false when we reach
fullscreen activity in the activity stack.

This was made visible by the following commit:
446ef1de8d373c1b017df8d19ebf9a47811fb402

Change-Id: I535c1283a4e26f5cf606375b837d4b7195324af0
Prevent Lockscreen album art from activating FLAG_KEEP_SCREEN_ON

This is a small fix to the showWallpaper method, in which a power
consumption problem has been introduced. This showWallpaper method
toggles the window flag FLAG_SHOW_WALLPAPER, when album art is being
shown in Lockscreen. It is important to set pixel format to
PixelFormat.OPAQUE if flag FLAG_SHOW_WALLPAPER is not being set.

If not, an application that uses window flag FLAG_KEEP_SCREEN_ON
will prevent the keyguard from going to sleep and drain battery.

Change-Id: I1808be28047977ae5ac4dd1168ea25cac8a55a78

Conflicts:

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