Revert "Clear All button added inRecent Panelview."

This reverts commit 7f6d30b1414ae0b723dd3724ec5e70196bc9e4ac.

Conflicts:
	core/java/android/provider/Settings.java
Recents: Clear all button for recent apps.

An icon will appear on navbar when there are apps available to be killed on recent apps.

Credits to @BigBrother1984 for kitkat porting from jellybean

Patchset 2: Tablet mode is deprecated now, so no need of multiple callbacks
Patchset 3: Remove copyright from unaffected files
Patchset 4: Remove unused imports

Change-Id: I93d1d4cb34325190b03ae3a0d40e1bc170c92d91

Conflicts:
	core/java/android/app/StatusBarManager.java
	packages/SystemUI/src/com/android/systemui/statusbar/phone/NavigationBarView.java