Decouple recents from status bar.

Remove remaining references to recents package from status bar.

Introduce in-process "components" to the existing SystemUI base class
to make component boundaries explicit, and implement Recents as the
first component.

Change-Id: Ieefd386379a1f46806b31f68a4cacd76c093aea4

Conflicts:
	packages/SystemUI/src/com/android/systemui/recent/Recents.java
	packages/SystemUI/src/com/android/systemui/statusbar/BaseStatusBar.java