Don't exclude CONTROLPARENT windows #17

The CONTROLPARENT filter was too restrictive (e.g. Beyond Compare did not appear)

But to avoid duplicate entries in the list:
- The window need to have no owner, or the owner window should not be visible
  (This improves handling of e.g. Password Manager XP and Inno Setup)

Further improvements:
- NOACTIVATE windows should be not included (This improves handling of TeamViewer)