message: active state for the play buttons
diff: @@ -15,8 +15,14 @@ export default class ToolBar extends React.Component {
  render() {
  return (
  <span>
  - { UiState.selectedTest.suite ? <PlayAll onClick={PlaybackState.startPlayingSuite} /> : null }
  - { UiState.selectedTest.test ? <PlayCurrent onClick={PlaybackState.startPlaying} /> : null }
  + { UiState.selectedTest.suite ? <PlayAll
  + isActive={PlaybackState.isPlaying && PlaybackState.currentRunningSuite}
  + onClick={PlaybackState.startPlayingSuite}
  + /> : null }
  + { UiState.selectedTest.test ? <PlayCurrent
  + isActive={PlaybackState.isPlaying && PlaybackState.currentRunningTest && !PlaybackState.currentRunningSuite}
  + onClick={PlaybackState.startPlaying}
  + /> : null }
  { PlaybackState.isPlaying ? <Stop onClick={PlaybackState.abortPlaying} /> : null }
  { PlaybackState.isPlaying ? <Pause /> : null }
  { !PlaybackState.isPlaying && UiState.selectedCommand ? <StepInto /> : null }
  