Fix constantly updating the power state
Fix dynamically change visible/enable for action bar items

Use ActionBar.findItem instead of Menu.findItem, so items on the action bar can
dynamically change visibility and enabled/disabled, on pre honeycomb devices,
i.e when using the actionbar compatibility code.
Fix bug where the power state was continuously updating.
Fix dynamically updating visible/enabled state for action bar items

Use ActionBar.findItem instead of Menu.findItem, so items on the action
bar can dynamically change visibility and enabled/disabled state on
pre-honeycomb devices, i.e when using the actionbar compatibility code.