Add "action type" select to select-features example

Making it possible to choose between three select interactions, one that works on "singleclick", one that works on "click", and one that works on "mousemove".

examples/select-features.html

@@ -33,7 +33,17 @@
 
         <div class="span12">
           <h4 id="title">Select features example</h4>
-          <p id="shortdesc">Example of using the Select interaction. Select features by clicking polygons. Hold the Shift-key to toggle the feature in the selection.</p>
+          <p id="shortdesc">Example of using the Select interaction. Choose between <code>Single-click</code>, <code>Click</code> and <code>Hover</code> as the event type for selection in the combobox below. When using <code>Single-click</code> or <code>Click</code> you can hold do <code>Shift</code> key to toggle the feature in the selection.</p>
+          <p>Note: when <code>Single-click</code> is used double-clicks won't select features. This in contrast to <code>Click</code>, where a double-click will both select the feature and zoom the map (because of the <code>DoubleClickZoom</code> interaction). Note that <code>Single-click</code> is less responsive than <code>Click</code> because of the delay it uses to detect double-clicks.</p>
+          <form class="form-inline">
+            <label>Action type &nbsp;</label>
+              <select id="type">
+                <option value="none" selected>None</option>
+                <option value="singleclick">Single-click</option>
+                <option value="click">Click</option>
+                <option value="mousemove">Hover</option>
+              </select>
+          </form>
           <div id="docs">
             <p>See the <a href="select-features.js" target="_blank">select-features.js source</a> to see how this is done.</p>
           </div>