title: Updating this.state.dataSource doesn't update ListView
body: <p>I have a ListView like:  </p>
  
  <pre><code>&lt;ListView
        dataSource={this.state.dataSource}
        renderRow={this.renderMovie}
        style={styles.listView}
  /&gt;
  </code></pre>
  
  <p>It displays rows like:</p>
  
  <pre><code>  &lt;View style={styles.container}&gt;
        &lt;TouchableHighlight onPress={this._onPressButton.bind(this,movie)}&gt;
  
          &lt;Image
            source={{uri: movie.uri}}
            style={styles.thumbnail}
          /&gt;
      &lt;/TouchableHighlight&gt;
      &lt;View style={styles.rightContainer}&gt;
        &lt;Text style={styles.title}&gt;{movie.id}&lt;/Text&gt;
        &lt;Text style={styles.year}&gt;{movie.votes}&lt;/Text&gt;
      &lt;/View&gt;
    &lt;/View&gt;
  </code></pre>
  
  <p>I have a function that updates this.state.dataSource with the number of "votes" a movie has.  But these changes aren't reflected in the UI, but when I log the this.state.dataSource, the changes are there.  Do I need to somehow re-render the rows?  Shouldn't they automatically change?</p>
  
  <p>Thanks!</p>