title: material design lite (MDL) button with icon
body: <p>in MDL there are two options: Normal Button: </p>
  
  <pre><code>    &lt;button className="mdl-button mdl-js-button"&gt;
        Continue with Facebook
      &lt;/button&gt;
  </code></pre>
  
  <p>And Icon Button:</p>
  
  <pre><code>    &lt;button className="mdl-button mdl-js-button mdl-button--icon"&gt;
        &lt;i className="material-icons"&gt;mood&lt;/i&gt;
      &lt;/button&gt;
  </code></pre>
  
  <p>How is it possible to have a button with icon to the very left, i.e. something like</p>
  
  <pre><code>    &lt;button className="mdl-button mdl-js-button mdl-button--raised mdl-button--icon-left"&gt;
        &lt;i className="material-icons"&gt;mood&lt;/i&gt; Continue with Facebook
      &lt;/button&gt;
  </code></pre>