title: detecting clicked tableView
body: <p>Regardless of selection, I need to know the tableview involved with a mouse click. Consider</p>
  
  <pre><code>func tableViewSelectionDidChange(notification: NSNotification) {
      self.selectedTableView = (notification.object as! NSTableView)
      switch selectedTableView {
      case oneTableView?:
          print("one")
          break
      case twoTableView?:
          print("two")
          break
      default:
          print("wtf \(selectedTableView)")
      }
  }
  </code></pre>
  
  <p>table/view 'two' is a detail of 'one'. Selecting a row in 'one' alters the content for tableview 'two' (header -> detail). But if the user clicked a row already selected, no notification as the selection did not change.  Basi I just need to know the last tableview / column clicked.</p>
  
  <p>Is mouseDown approach better (way more difficult) but I do <strong>not</strong> see objective-c or 'UI' equivalent delegate methods in the AppKit -> NSTableView -> NSTableView for column or row selection methods?</p>