Checkbox Selector v1.1

Press the Shift-Key and make a rectangle-selection with the mouse by clicking-and-dragging. All checkboxes within the selection change their status:
- Unchecked checkboxes will be checked
- Checked checkboxes will be unchecked
Press the Shift-Key and make a rectangle-selection with the mouse by clicking-and-dragging. All checkboxes within the selection change their status: