message: pass onClear to DatePickerWrapper
diff: @@ -96,6 +96,7 @@ export default class DatePickerWrapper extends PickerBase {
  ref={(node) => { this.wrapper = node; }}
  value={value}
  format={format}
  + onClear={this.handleClear}
  onAccept={this.handleAccept}
  onChange={this.handleTextFieldChange}
  onDismiss={this.handleDismiss}
  