Update pannellum.js

this is a workarround for the unsupported fullscreen api on ios (iphones/ipads).
i have added a new config value "workaroundFullscreen" (by default on) which now forces to show the fullscreen button.
on click it maximizes, additionally to the fullscreen api function, the pannellum container class inside the browser.

src/js/pannellum.js

@@ -103,7 +103,7 @@ var defaultConfig = {
     showZoomCtrl: true,
     autoLoad: false,
     showControls: true,
-    workaroundFullscreen: true,
+    workaroundFullscreen: true, //set true if fullscreen api is not supported
     orientationOnByDefault: false,
     hotSpotDebug: false,
     backgroundColor: [0, 0, 0],