Configure maps with TileManger instances (and not the other way around)

This resolves issues with destroying caches on window unload, and makes
cache sharing among maps less confusing to configure.

examples/mobile-wmts-vienna.js

@@ -1,4 +1,4 @@
-var map, tileManager;
+var map;
 
 (function() {
     // Set document language for css content 
@@ -99,6 +99,7 @@ var map, tileManager;
         maxExtent: [-20037508.34, -20037508.34, 20037508.34, 20037508.34],
         maxResolution: 156543.0339,
         numZoomLevels: 20,
+        tileManager: new OpenLayers.TileManager(),
         controls: [
             new OpenLayers.Control.Navigation({
                 mouseWheelOptions: {
@@ -124,7 +125,6 @@ var map, tileManager;
             }
         }
     });
-    tileManager = new OpenLayers.TileManager({map: map});
     layerPanel.activateControl(mapButton);
     layerPanel.activateControl(labelButton);