title: Angular doesn't validating date type
body: <p>I'm trying to use input[date] in my form, but angularjs doesn't validate any date:</p>
  
  <pre><code>&lt;form name="myForm"&gt;
      {{birthday}} &lt;br/&gt;
      &lt;input type="date" ng-model="birthday" id="birthday" name="birthday"&gt;&lt;/input&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>If I try to put "alex" inside the input, it accepts!</p>
  
  <p>JSFiddle: <a href="http://jsfiddle.net/3GKeM/2/" rel="nofollow">http://jsfiddle.net/3GKeM/2/</a> (please try with firefox)</p>