Quick Settings: Swipe to switch

Adds the ability to switch to/from Quick Settings, using a sideways
swipe gesture.

Video demonstration: http://www.youtube.com/watch?v=jZaDVBIFAuA

Change-Id: I95aaa4fa1b0e8f74537e48936fe2c0f9f15671dd

Conflicts:

	packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java