Add spiral to Madrid animation example

examples/animation.html

@@ -39,6 +39,7 @@
         <button id="bounce-to-istanbul">Bounce to Istanbul</button>
         <button id="spin-to-rome">Spin to Rome</button>
         <button id="fly-to-bern">Fly to Bern</button>
+        <button id="spiral-to-madrid">Spiral to Madrid</button>
       </div>
 
       <div class="row-fluid">