revamp navbar

Change-Id: Ice3ca1d25f4a53215ab2c6e34d62a7f3db01f19f

Conflicts:

	core/java/android/provider/Settings.java
	packages/SystemUI/res/drawable-hdpi/ic_sysbar_null.png
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/KeyButtonView.java