Enable smooth panning. Notice the magnifier no longer tracks focus.

I added the following check for the smooth_pan instance variable in ZoomMove. Before it was always using _panTo and never using _hopTop on a focus change, regardless of smooth panning option.

    if start_coord and self.smooth_pan:
      self._panTo(end_coord, start_coord)
    else:
      self._hopTo(end_coord)

This fixes part of the problem by allowing the magnifier to work when panning if off.