title: Material UI component reference does not work
body: <p>I am building a little chat application.i have used Material UI TextField to input user message. but i can't refer it. I read about this. they said that they do not support for <code>refs</code>. 
  this is my code. and it works.</p>
  
  <pre><code>class App extends Component {
    constructor() {
      super();
      this.state = {
        q: "default"
      };
  
    }
    handleChanges(val) {
      this.setState({ q: val });
    }
    handleSearch(val) {
      this.setState({ q: val });
      console.log(this.state.q);
    }
    render() {
      return (
        &lt;div className="App"&gt;
          &lt;h1&gt;  {this.state.q}&lt;/h1&gt;
          &lt;Row className="show-grid"&gt;
            &lt;Col sm={2} md={4} className="contact"&gt;&lt;h5&gt;contact&lt;/h5&gt;&lt;br /&gt;&lt;/Col&gt;
            &lt;Col sm={10} md={8} className="chat grid-border"&gt;&lt;h5&gt;chat&lt;/h5&gt;&lt;br /&gt;
              &lt;div className="history"&gt;&lt;/div&gt;
              &lt;div className="message top-border"&gt;
  
                &lt;input type="text" ref="question" onChange={(e) =&gt; { this.handleChanges(this.refs.question.value) }} /&gt;
                &lt;MuiThemeProvider&gt;
                  &lt;FlatButton label="Primary" primary={true} onTouchTap={(e) =&gt; { e.preventDefault(); this.handleSearch(this.refs.question.value); }} /&gt;
                &lt;/MuiThemeProvider&gt;
  
              &lt;/div&gt;
            &lt;/Col&gt;
          &lt;/Row&gt;{/*show-grid ends here*/}
        &lt;/div&gt;
      );
    }
  }
  export default App;
  </code></pre>
  
  <p>If i used this material UI <code>TextField</code> instead of native HTML input tag it does not get the value from the reference.</p>
  
  <pre><code>&lt;MuiThemeProvider&gt;
         &lt;TextField hintText="Ask your question" fullWidth={true} multiLine={true} rows={2} rowsMax={4} type="text" ref="question" onChange={(e) =&gt; { this.handleChanges(this.refs.question.value) }}/&gt;
  &lt;/MuiThemeProvider&gt; 
  </code></pre>
  
  <p>Is there any workaround or alternative UI library for this ?</p>