Use on both ends of skim pass

The following example shows a retract and cutoff operation using the default behavior (Use on both ends of skim passes disabled):

1. End of retract pass 1, wire retracts by the Retract Length:

2. End of retract pass 2, wire retracts back to the start point:

3. End of retract pass 3, wire retracts by the Retract Length:

4. End of cutoff pass 1, wire retracts back to the start point:

5. End of cutoff pass 2, wire retracts by the Retract Length:

This is the same example with Use on both ends of skim passes enabled:

1. End of retract pass 1, wire retracts by the Retract Length:

2. End of retract pass 2, wire retracts by the Retract Length:

3. End of retract pass 3, wire retracts by the Retract Length:

4. End of cutoff pass 1, wire retracts by the Retract Length:

5. End of cutoff pass 2, wire retracts by the Retract Length: