title: Remove or change the calendar icon from angular material datepicker
body: <p>I was using <a href="https://material.angularjs.org" rel="noreferrer"><code>angular material</code></a>. I find it very cool, well designed and user friendly.
   I was trying to  change or remove the calendar <code>icon</code> on <code>datepicker</code> directive. </p>
  
  <pre><code>&lt;md-datepicker ng-model="myDate" md-placeholder="Enter date" &gt;&lt;/md-datepicker&gt;
  </code></pre>
  
  <p>The default icon is very good but i want to skip the icon in some case. well i can use svg icon using md-icon like this </p>
  
  <pre><code> &lt;md-icon md-svg-src="calendar.svg"&gt;&lt;/md-icon&gt;
  </code></pre>
  
  <p>Here is my <a href="http://plnkr.co/edit/GqAsAQ1PDUZ2nU5xo4Q0?p=preview" rel="noreferrer">sample plunker</a>. Suggest me some idea to change/remove the default icon on datepicker. </p>