Keep Construction Lines in V4

 From:  Frenchy Pilou (PILOU)
9800.4 In reply to 9800.3 
I took the code from here (should works also in the V3 (tested)
http://kyticka.webzdarma.cz/3d/moi/#KeepCLine

EDITED: 10 May 2020 by PILOU