gladevcp: add optional callbacks for SIGINT and SIGTERM
gladevcp: add optional callbacks for SIGINT and SIGTERM

if a handler 'on_unix_signal' is defined, then associate it with ŚIGTERM
and SIGINT. The handler signature is: on_unix_signal([self], signum, frame)

this is to assure that persistent state can be saved even if the
script is terminated by a signal, e.g. when hitting Ctrl-C to terminate
the linuxcnc script

mhaberler/machinekit,jaguarcat79/ILC-with-LinuxCNC,narogon/linuxcnc,cdsteinkuehler/MachineKit,RunningLight/machinekit,ikcalB/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,bobvanderlinden/machinekit,cdsteinkuehler/linuxcnc,araisrobo/linuxcnc,araisrobo/machinekit,ArcEye/MK-Qt5,narogon/linuxcnc,araisrobo/linuxcnc,kinsamanka/machinekit,ikcalB/linuxcnc-mirror,unseenlaser/machinekit,Cid427/machinekit,EqAfrica/machinekit,araisrobo/machinekit,bmwiedemann/linuxcnc-mirror,cdsteinkuehler/linuxcnc,unseenlaser/linuxcnc,mhaberler/machinekit,bobvanderlinden/machinekit,cdsteinkuehler/MachineKit,strahlex/machinekit,cnc-club/linuxcnc,mhaberler/machinekit,RunningLight/machinekit,aschiffler/linuxcnc,cnc-club/linuxcnc,ianmcmahon/linuxcnc-mirror,araisrobo/machinekit,bobvanderlinden/machinekit,ikcalB/linuxcnc-mirror,mhaberler/machinekit,bmwiedemann/linuxcnc-mirror,Cid427/machinekit,ArcEye/machinekit-testing,aschiffler/linuxcnc,jaguarcat79/ILC-with-LinuxCNC,ikcalB/linuxcnc-mirror,mhaberler/machinekit,cdsteinkuehler/linuxcnc,cnc-club/linuxcnc,ianmcmahon/linuxcnc-mirror,kinsamanka/machinekit,unseenlaser/machinekit,bobvanderlinden/machinekit,ianmcmahon/linuxcnc-mirror,unseenlaser/linuxcnc,unseenlaser/linuxcnc,ianmcmahon/linuxcnc-mirror,narogon/linuxcnc,bobvanderlinden/machinekit,kinsamanka/machinekit,RunningLight/machinekit,aschiffler/linuxcnc,jaguarcat79/ILC-with-LinuxCNC,bmwiedemann/linuxcnc-mirror,mhaberler/machinekit,araisrobo/machinekit,cdsteinkuehler/MachineKit,RunningLight/machinekit,Cid427/machinekit,jaguarcat79/ILC-with-LinuxCNC,unseenlaser/linuxcnc,ArcEye/machinekit-testing,Cid427/machinekit,araisrobo/machinekit,ianmcmahon/linuxcnc-mirror,cnc-club/linuxcnc,unseenlaser/machinekit,EqAfrica/machinekit,strahlex/machinekit,unseenlaser/linuxcnc,mhaberler/machinekit,araisrobo/machinekit,bobvanderlinden/machinekit,strahlex/machinekit,mhaberler/machinekit,cnc-club/linuxcnc,unseenlaser/machinekit,kinsamanka/machinekit,ArcEye/machinekit-testing,ikcalB/linuxcnc-mirror,ArcEye/MK-Qt5,bmwiedemann/linuxcnc-mirror,strahlex/machinekit,ArcEye/machinekit-testing,ArcEye/MK-Qt5,cdsteinkuehler/linuxcnc,strahlex/machinekit,ianmcmahon/linuxcnc-mirror,aschiffler/linuxcnc,unseenlaser/machinekit,bmwiedemann/linuxcnc-mirror,strahlex/machinekit,strahlex/machinekit,cdsteinkuehler/MachineKit,araisrobo/linuxcnc,cnc-club/linuxcnc,EqAfrica/machinekit,araisrobo/machinekit,unseenlaser/machinekit,ArcEye/machinekit-testing,ikcalB/linuxcnc-mirror,araisrobo/linuxcnc,araisrobo/linuxcnc,ArcEye/MK-Qt5,cdsteinkuehler/MachineKit,unseenlaser/machinekit,RunningLight/machinekit,ArcEye/MK-Qt5,cdsteinkuehler/linuxcnc,ArcEye/machinekit-testing,cdsteinkuehler/MachineKit,EqAfrica/machinekit,ikcalB/linuxcnc-mirror,cdsteinkuehler/linuxcnc,bobvanderlinden/machinekit,Cid427/machinekit,EqAfrica/machinekit,Cid427/machinekit,kinsamanka/machinekit,ArcEye/MK-Qt5,araisrobo/machinekit,RunningLight/machinekit,ArcEye/machinekit-testing,narogon/linuxcnc,EqAfrica/machinekit,EqAfrica/machinekit,ArcEye/MK-Qt5,kinsamanka/machinekit,Cid427/machinekit,kinsamanka/machinekit,unseenlaser/machinekit,jaguarcat79/ILC-with-LinuxCNC,kinsamanka/machinekit,RunningLight/machinekit,aschiffler/linuxcnc,ArcEye/MK-Qt5,bmwiedemann/linuxcnc-mirror,cnc-club/linuxcnc,bobvanderlinden/machinekit,ArcEye/machinekit-testing,EqAfrica/machinekit,araisrobo/machinekit,narogon/linuxcnc,RunningLight/machinekit,Cid427/machinekit,ianmcmahon/linuxcnc-mirror