message: call the abort function
diff: @@ -17,7 +17,7 @@ export default class ToolBar extends React.Component {
  <span>
  { UiState.selectedTest.suite ? <PlayAll onClick={PlaybackState.startPlayingSuite} /> : null }
  { UiState.selectedTest.test ? <PlayCurrent onClick={PlaybackState.startPlaying} /> : null }
  - { PlaybackState.isPlaying ? <Stop /> : null }
  + { PlaybackState.isPlaying ? <Stop onClick={PlaybackState.abortPlaying} /> : null }
  { PlaybackState.isPlaying ? <Pause /> : null }
  { !PlaybackState.isPlaying && UiState.selectedCommand ? <StepInto /> : null }
  <SpeedGauge />
  