SystemUI: fix wrong statusbar background.

If we turned off screen while some panel was visible than
background of PhoneStatusBarView will not be updated because we receiving single
panelExpansionChanged call and after super.panelExpansionChanged mFadingPanel
will be null (onAllPanelsCollapsed cause this).

Allow updating background when mFadingPanel is null.

Change-Id: Ib123f27500790c1b7ec787b7e433372629daa08d
Development shortcut in StatusBar and Recent Panel

It enables the wipe data and application force close option in the
recent tasks list and in the notification area. These options will
be available only if the Development shortcut option is enabled.

Change-Id: Ia4e1d040e8eade5afe118dd62bc28c86381c03e6
Merge remote-tracking branch 'cm/cm-11.0' into wszf