Unreliable dragging of screen controls when hovering over other controls text or over the end edges of the screen

[samuelventura]

• Passing the temprary frame over its original control stops receiving the move event.
• Moving the temprary frame beyond the right and bottom edge of the screen also stops receiving the move event
• Strangely the cleanup is being called without getting a mouseUp event!

[samuelventura]

To make dragging reliable:

• Ensure label text is not overflowing. Smaller font size prevent the problem.
• Keep the controls withing the screen area by restricting going beyond borders
• Controls that get beyond the borders by a gridXY change can reliably be dragged back in
• Not really needed in the end, but added non selectable style with

  svg text {
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  }