Bug fixes.

- G38.x was not printing correctly in the $G g-code state reports. Now
fixed.

- When investigating the above issue, it was noticed that G38.x
wouldn’t show at all, but instead a G0 would be printed. This was
unlike the v0.9j master build. It turned out volatile variables do not
like to be defined inside a C struct. These are undefined on how to be
handled. Once pulled out, all weird issues went away.

- Also changed two ‘sizeof()’ statements in the mc_probe() and
probe_state_monitor() functions to be more robust later on.

- Updated the commit logs to individual files for each minor release.
Forgot to update the generating script to account for this.

grbl/system.c

@@ -49,13 +49,13 @@ ISR(CONTROL_INT_vect)
     if (bit_istrue(pin,bit(RESET_BIT))) {
       mc_reset();
     } else if (bit_istrue(pin,bit(CYCLE_START_BIT))) {
-      bit_true(sys.rt_exec_state, EXEC_CYCLE_START);
+      bit_true(sys_rt_exec_state, EXEC_CYCLE_START);
     #ifndef ENABLE_SAFETY_DOOR_INPUT_PIN
       } else if (bit_istrue(pin,bit(FEED_HOLD_BIT))) {
-        bit_true(sys.rt_exec_state, EXEC_FEED_HOLD); 
+        bit_true(sys_rt_exec_state, EXEC_FEED_HOLD); 
     #else
       } else if (bit_istrue(pin,bit(SAFETY_DOOR_BIT))) {
-        bit_true(sys.rt_exec_state, EXEC_SAFETY_DOOR);
+        bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR);
     #endif
     } 
   }