title: React Checkbox not sending onChange
body: <p>TLDR: Use defaultChecked instead of checked, working <a href="http://jsbin.com/mecimayawe/1/edit?js,output" rel="noreferrer">jsbin</a>.</p>
  
  <p>Trying to setup a simple checkbox that will cross out its label text when it is checked.  For some reason handleChange is not getting fired when I use the component.  Can anyone explain what I'm doing wrong?</p>
  
  <pre class="lang-js prettyprint-override"><code>var CrossoutCheckbox = React.createClass({
    getInitialState: function () {
      return {
          complete: (!!this.props.complete) || false
        };
    },
    handleChange: function(){
      console.log('handleChange', this.refs.complete.checked); // Never gets logged
      this.setState({
        complete: this.refs.complete.checked
      });
    },
    render: function(){
      var labelStyle={
        'text-decoration': this.state.complete?'line-through':''
      };
      return (
        &lt;span&gt;
          &lt;label style={labelStyle}&gt;
            &lt;input
              type="checkbox"
              checked={this.state.complete}
              ref="complete"
              onChange={this.handleChange}
            /&gt;
            {this.props.text}
          &lt;/label&gt;
        &lt;/span&gt;
      );
    }
  });
  </code></pre>
  
  <p>Usage:</p>
  
  <pre class="lang-js prettyprint-override"><code>React.renderComponent(CrossoutCheckbox({text: "Text Text", complete: false}), mountNode);
  </code></pre>
  
  <p>Solution:</p>
  
  <p>Using checked doesn't let the underlying value change (apparently) and thus doesn't call the onChange handler.  Switching to defaultChecked seems to fix this:</p>
  
  <pre class="lang-js prettyprint-override"><code>var CrossoutCheckbox = React.createClass({
    getInitialState: function () {
      return {
          complete: (!!this.props.complete) || false
        };
    },
    handleChange: function(){
      this.setState({
        complete: !this.state.complete
      });
    },
    render: function(){
      var labelStyle={
        'text-decoration': this.state.complete?'line-through':''
      };
      return (
        &lt;span&gt;
          &lt;label style={labelStyle}&gt;
            &lt;input
              type="checkbox"
              defaultChecked={this.state.complete}
              ref="complete"
              onChange={this.handleChange}
            /&gt;
            {this.props.text}
          &lt;/label&gt;
        &lt;/span&gt;
      );
    }
  });
  </code></pre>