Added menu option to hide/show main notification.
Put android:label attribute in the right place for widget.
Update widget image even when not using notification.  (Erroneously was updated in prepareNotification() before.)
Use different method to swap show/hide notification menu, hoping to keep to two rows on devices with menu buttons.  Didn't work, then forced the issue by rearranging order.
Keep track of actual number of widgets, since AppWidgetManager.getAppWidgetIds() returns defunct IDs. Unfortunately, the only workaround for existing widgets from 8.1.0 is to remove all widgets to reset count.  Main window then disallows closing if there are any widgets.
Make Service closeable/uncloseable based on AppWidgetProvider's onEnabled()/onDisabled().
Store widgetsPresent boolean in sp_store to be more robust (widget could be removed while Service is temporarily stopped or even force-closed).
Released Pro-8.1.1
Merge branch 'widget'