[Paciente8159/uCNC PR#64] v1.2.1

Version 1.2.1 is a minor revision from the previous version. This version aims mainly to improve the overall response of µCNC and fix a few bugs.
The following things were changed:

Added

– added support for G10 L2 P0 (current coordinate system) (#61)
– implemented codes M0 and M1. M60 is also supported but behave like M0 (#58)

Changed

– revised and improved interlocking system that is more straight forward (code flow). Also this makes µCNC act more inline with the interface described by Grbl (#63)
– all hard/soft limit alarms cause the firmware to lock until software reset is issued as described by Grbl (#63)
– readapted homing and probing to the new interlocking logic (#63)
– startup code improvements (#62)
– modified µCNC to execute synchronous motions at motion control level. This reduces the pipeline travelling of the code at the expense of additional restart delay that is neglectable (#59)
– dropped the Abort status in favor of the Alarm status to be more Grbl compliant (#59)
– blocked status reports during startup blocks to prevent startup block ill-formated strings that were causing the interface software to correctly recognize the responses (#59)

Fixed

– fixed axis drifting after homing. This happened on all motions until an explicit coordinate was set for that axis (#63)
– fixed hidden probe alarm status that only showed if other input alarms were active (#63)
– G92 and G5x.x offset calculations (#61)
– fixed inch report mode converted values output (#60)