[iitcm] tweaks to fullscreen menu item

Use other icon for returning from fullscreen if shown as action. If shown in the action overflow, provide a chechbox to show current state.

mobile/src/com/cradle/iitc_mobile/IITC_WebView.java

@@ -221,6 +221,7 @@ public class IITC_WebView extends WebView {
             loadUrl("javascript: $('#updatestatus').show();");
         }
         mIitc.getWindow().setAttributes(attrs);
+        mIitc.invalidateOptionsMenu();
     }
 
     void updateFullscreenStatus() {