v1.1c: New sleep mode. Laser mode and other bug fixes.

- New $SLP sleep mode that will disable spindle, coolant, and stepper
enable pins. Allows users to disable their steppers without having to
alter their settings. A reset is required to exit and re-initializes in
alarm state.

- Laser mode wasn’t updating the spindle PWM correctly (effected
spindle speed overrides) and not checking for modal states either.
Fixed both issues.

- While in laser mode, parking motions are ignored, since the power off
delay with the retract motion would burn the material. It will just
turn off and not move. A restore immediately powers up and resumes. No
delays.

- Changing rpm max and min settings did not update the spindle PWM
calculations. Now fixed.

- Increased default planner buffer from 16 to 17 block. It seems to be
stable, but need to monitor this carefully.

- Removed software debounce routine for limit pins. Obsolete.

- Fixed a couple parking motion bugs. One related to restoring
incorrectly and the other the parking rate wasn’t compatible with the
planner structs.

- Fixed a bug caused by refactoring the critical alarms in a recent
push. Soft limits weren’t invoking a critical alarm.

- Updated the documentation with the new sleep feature and added some
more details to the change summary.

grbl/motion_control.c

@@ -290,16 +290,6 @@ uint8_t mc_probe_cycle(float *target, plan_line_data_t *pl_data, uint8_t is_prob
   plan_reset(); // Reset planner buffer. Zero planner positions. Ensure probing motion is cleared.
   plan_sync_position(); // Sync planner position to current machine position.
 
-  // TODO: Update the g-code parser code to not require this target calculation but uses a gc_sync_position() call.
-  // NOTE: The target[] variable updated here will be sent back and synced with the g-code parser.
-  
-  //!!! This is the problem. Need to set the g-code parser to update the position appropriately.
-  // - Probe initialization fail: Retain current position.
-  // - Probe successful: Update new positions across everything, since held before the target.
-  // - Probe did not contact (alarm or not): Copy original target position as normal
-   
-//   system_convert_array_steps_to_mpos(target, sys_position);
-
   #ifdef MESSAGE_PROBE_COORDINATES
     // All done! Output the probe position as message.
     report_probe_parameters();