v1.1b: Tweaked Bf reports, jogging doc, saved another 160 bytes, minor bug fixes

- Increment to v1.1b due to status report tweak.

- Tweaked the buffer state status reports to show bytes and blocks
available, rather than in use. This does not require knowing the buffer
sizes beforehand. It’s implicit.

- Also, since buffer states are not used by most devs (after
inquiries), it is no longer enabled by default and a status mask option
was added for this.

- Fixed some typos and updated for the report tweak in the
documentation.

- Wrote a joystick implementation concept in the jogging markdown
document. Outlines how to get a low-latency feel to a joystick (and
other input devices).

- Removed XON/XOFF support. It’s not used by anyone because of its
inherent problems. Remains in older versions for reference.

- Added a compile option on how to handle the probe position during a
check mode.

- Fixed a jogging bug. If G93 is the modal state before a jogging
motion, the feed rate did not get calculated correctly. Fixed the issue.

- Refactored some code to save another 160+ bytes. Included an improved
float vector comparison macro and reducing a few large and repetitive
function calls.

- Fixed a probing bug (existing in v0.9 too) where the target positions
were not set correct and error handling was improper.

grbl/motion_control.h

@@ -46,7 +46,7 @@ void mc_dwell(float seconds);
 void mc_homing_cycle();
 
 // Perform tool length probe cycle. Requires probe switch.
-void mc_probe_cycle(float *target, plan_line_data_t *pl_data, uint8_t is_probe_away, uint8_t is_no_error);
+uint8_t mc_probe_cycle(float *target, plan_line_data_t *pl_data, uint8_t is_probe_away, uint8_t is_no_error);
 
 // Plans and executes the single special motion case for parking. Independent of main planner buffer.
 void mc_parking_motion(float *parking_target, plan_line_data_t *pl_data);