"Clear all" button on recent apps

Port forward from cm-10.2

Change-Id: I9ebcf22f85957f61caefb14e0efd4cf2978d92cd

Conflicts:
	packages/SystemUI/src/com/android/systemui/recent/RecentsHorizontalScrollView.java
SystemUI: unbreak RecentsPanel with translucent decors.

Change-Id: Ibcc4f5fc11109c0f2c149e66b7531e8c9ea79ae1

Conflicts:
	packages/SystemUI/src/com/android/systemui/recent/RecentsPanelView.java
Add touch feedback to the clear all recents button

5 minutes of Photoshop™.

Change-Id: Idf8c97cf08a192605208cbee6f2ae41e0798e8d1