Added complete stop delay at the end of all motion. Moved grbl preprocessor script into a new repository.

Added a very short (25 ms) user-definable delay before the steppers are
disabled at the motors are disabled and grbl goes idle. This ensures
any residual inertia at the end of the last motion does not cause the
axes to drift and grbl to lose its position when manually entering
g-code or when performing a tool change and starting the next
operation.

stepper.c

@@ -84,6 +84,9 @@ void st_wake_up() {
 }
 
 static void st_go_idle() {
+  // Force stepper dwell to lock axes for a defined amount of time to ensure the axes come to a complete
+  // stop and not drift from residual inertial forces at the end of the last movement.
+  _delay_ms(STEPPER_IDLE_LOCK_TIME);   
   // Disable steppers by setting stepper disable
   STEPPERS_DISABLE_PORT |= (1<<STEPPERS_DISABLE_BIT);
   // Disable stepper driver interrupt