Replace mouseMove event condition by pointerMove

The original browser event was used to catch the mousemove event,
but in IE the 'pointermove' event is returned instead. So, instead
of using the original event, we use the map browser event, which
is always 'pointermove'.

examples/select-features.html

@@ -41,7 +41,7 @@
                 <option value="none" selected>None</option>
                 <option value="singleclick">Single-click</option>
                 <option value="click">Click</option>
-                <option value="mousemove">Hover</option>
+                <option value="pointermove">Hover</option>
               </select>
           </form>
           <div id="docs">