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/gcode.h

@@ -123,7 +123,6 @@
 // Modal Group G12: Active work coordinate system
 // N/A: Stores coordinate system value (54-59) to change to.
 
-
 // Define parameter word mapping.
 #define WORD_F  0
 #define WORD_I  1
@@ -139,6 +138,23 @@
 #define WORD_Y  11
 #define WORD_Z  12
 
+// Define g-code parser position updating flags
+#define GC_UPDATE_POS_TARGET   0
+#define GC_UPDATE_POS_SYSTEM   1
+#define GC_UPDATE_POS_NONE     2
+
+// Define probe cycle exit states and assign proper position updating.
+#define GC_PROBE_FOUND      GC_UPDATE_POS_SYSTEM
+#define GC_PROBE_ABORT      GC_UPDATE_POS_NONE
+#define GC_PROBE_FAIL_INIT  GC_UPDATE_POS_NONE
+#define GC_PROBE_FAIL_END   GC_UPDATE_POS_TARGET
+#ifdef SET_CHECK_MODE_PROBE_TO_START
+  #define GC_PROBE_CHECK_MODE   GC_UPDATE_POS_NONE  
+#else
+  #define GC_PROBE_CHECK_MODE   GC_UPDATE_POS_TARGET
+#endif
+
+
 
 // NOTE: When this struct is zeroed, the above defines set the defaults for the system.
 typedef struct {