task:  fix for RFL with subroutines
task:  fix for RFL with subroutines

rationale: consider lines of the main program only when starting to execute
(emcTaskPlanLevel() == 0), not when reading or executing
subroutines (emcTaskPlanLevel() > 0)

The following example now can correctly started from any  line:

(debug, pre testsub declaration)

o<testsub> sub
(debug, testsub called)
o<testsub> endsub

(debug, pre testsub call)
o<testsub> call
(debug, post testsub call)
m2

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