Modified to output LMN Marlin friendly gcode

A few changes to gcode generation:
+ M3 commands include laser intensity (S[0-100])
+ G00 (move w/laser off) get feedrate independent of cut moves
+ G01-03 (cut moves) get feedrate independent of G00 rate
+ Option to insert home all (G28) before starting
+ All above get fields/toggle in dialog
- Removed header and footer in out put (was causing me issues)
+/- more appropriate comments