PIE: option for Pie to maintain its position, disregarding orientation changes (useful for gaming)

Change-Id: I2bde8ee6f6fdff602a1241d4da7fd88ed3216477

Conflicts:
	core/java/android/provider/Settings.java
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java
allow widgets to minimize in extended desktop

Change-Id: If4c7556ebcf0b5ddf7dc93ec56c8fb64dedc9723
Revert "SystemUI: unregister ContentObserver"

This reverts commit 885cb6cb17435a9241d35a74ffb30ed6f3f00f8a.

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/NavigationBarView.java

Change-Id: I163e26a8e3c92e916603919df18adebda9bd3e86