Add extra error checking to step_types:  only allow types between 0 and MAX_STEP_TYPE
Add extra error checking to step_types:  only allow types between 0 and MAX_STEP_TYPE

ianmcmahon/linuxcnc-mirror,ianmcmahon/linuxcnc-mirror,unseenlaser/machinekit,Cid427/machinekit,mhaberler/machinekit,EqAfrica/machinekit,ArcEye/machinekit-testing,ikcalB/linuxcnc-mirror,cnc-club/linuxcnc,cnc-club/linuxcnc,mhaberler/machinekit,EqAfrica/machinekit,araisrobo/linuxcnc,mhaberler/machinekit,araisrobo/linuxcnc,ianmcmahon/linuxcnc-mirror,ArcEye/MK-Qt5,ArcEye/machinekit-testing,bmwiedemann/linuxcnc-mirror,strahlex/machinekit,mhaberler/machinekit,kinsamanka/machinekit,unseenlaser/machinekit,EqAfrica/machinekit,EqAfrica/machinekit,ArcEye/machinekit-testing,unseenlaser/linuxcnc,kinsamanka/machinekit,ArcEye/MK-Qt5,narogon/linuxcnc,ianmcmahon/linuxcnc-mirror,RunningLight/machinekit,aschiffler/linuxcnc,cdsteinkuehler/MachineKit,ianmcmahon/linuxcnc-mirror,unseenlaser/machinekit,strahlex/machinekit,cnc-club/linuxcnc,RunningLight/machinekit,yishinli/emc2,Cid427/machinekit,strahlex/machinekit,ianmcmahon/linuxcnc-mirror,EqAfrica/machinekit,aschiffler/linuxcnc,mhaberler/machinekit,bobvanderlinden/machinekit,cdsteinkuehler/linuxcnc,unseenlaser/linuxcnc,RunningLight/machinekit,unseenlaser/linuxcnc,cnc-club/linuxcnc,ikcalB/linuxcnc-mirror,strahlex/machinekit,yishinli/emc2,RunningLight/machinekit,jaguarcat79/ILC-with-LinuxCNC,ikcalB/linuxcnc-mirror,cdsteinkuehler/MachineKit,unseenlaser/linuxcnc,cdsteinkuehler/linuxcnc,bobvanderlinden/machinekit,unseenlaser/machinekit,EqAfrica/machinekit,kinsamanka/machinekit,kinsamanka/machinekit,ArcEye/machinekit-testing,ArcEye/MK-Qt5,RunningLight/machinekit,ArcEye/machinekit-testing,EqAfrica/machinekit,jaguarcat79/ILC-with-LinuxCNC,bobvanderlinden/machinekit,araisrobo/machinekit,ArcEye/MK-Qt5,araisrobo/machinekit,araisrobo/machinekit,ikcalB/linuxcnc-mirror,cnc-club/linuxcnc,Cid427/machinekit,ArcEye/machinekit-testing,ArcEye/MK-Qt5,narogon/linuxcnc,bobvanderlinden/machinekit,cdsteinkuehler/MachineKit,bmwiedemann/linuxcnc-mirror,narogon/linuxcnc,araisrobo/machinekit,ArcEye/machinekit-testing,kinsamanka/machinekit,kinsamanka/machinekit,jaguarcat79/ILC-with-LinuxCNC,unseenlaser/machinekit,unseenlaser/machinekit,Cid427/machinekit,Cid427/machinekit,aschiffler/linuxcnc,cdsteinkuehler/MachineKit,mhaberler/machinekit,araisrobo/machinekit,ArcEye/machinekit-testing,strahlex/machinekit,cdsteinkuehler/linuxcnc,cdsteinkuehler/linuxcnc,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,araisrobo/machinekit,strahlex/machinekit,narogon/linuxcnc,cdsteinkuehler/linuxcnc,Cid427/machinekit,araisrobo/machinekit,cdsteinkuehler/MachineKit,bmwiedemann/linuxcnc-mirror,mhaberler/machinekit,RunningLight/machinekit,bobvanderlinden/machinekit,aschiffler/linuxcnc,ikcalB/linuxcnc-mirror,Cid427/machinekit,araisrobo/machinekit,unseenlaser/machinekit,ArcEye/MK-Qt5,EqAfrica/machinekit,bobvanderlinden/machinekit,kinsamanka/machinekit,cnc-club/linuxcnc,ianmcmahon/linuxcnc-mirror,narogon/linuxcnc,RunningLight/machinekit,yishinli/emc2,Cid427/machinekit,bmwiedemann/linuxcnc-mirror,aschiffler/linuxcnc,unseenlaser/linuxcnc,jaguarcat79/ILC-with-LinuxCNC,unseenlaser/machinekit,araisrobo/linuxcnc,cnc-club/linuxcnc,araisrobo/linuxcnc,ArcEye/MK-Qt5,ikcalB/linuxcnc-mirror,ArcEye/MK-Qt5,ikcalB/linuxcnc-mirror,jaguarcat79/ILC-with-LinuxCNC,bmwiedemann/linuxcnc-mirror,bobvanderlinden/machinekit,bobvanderlinden/machinekit,cdsteinkuehler/linuxcnc,araisrobo/machinekit,kinsamanka/machinekit,strahlex/machinekit,araisrobo/linuxcnc,mhaberler/machinekit,yishinli/emc2,RunningLight/machinekit,cdsteinkuehler/MachineKit