Attempt to handle IE >= 10 pointer events

Using the same technique as Leaflet, this relays MSPointer events to touch
events. Using the simulator, I can verify that even pinch-zoom works with
this change, but the visual experience is a bit jumpy. Would be great if
people could test this on physical touch devices and see how it looks/feels
there.

examples/mobile-wmts-vienna.css

@@ -12,6 +12,9 @@ html, body, #map {
 #title, #tags, #shortdesc {
     display: none;
 }
+div.olMapViewport {
+    -ms-touch-action: none;
+}
 
 /* Turn on GPU support where available */
 .olTileImage {