linenumber test spike
trying to fix line numbering for 0 moves - in progress
Real fix for end-of-motion line numbering
cleanup stale code
rm spare character, added hex
Merge branch 'line-numbering' into async-gcode

Conflicts:
	grbl.hex
	limits.c
	stepper.c
report line number after dwell, fix homing line numbering, sim dwell
cleanup comments