- Line number tracking was getting truncated at 255, since it was using
wrong variable type. Fixed it with a trunc().
- Increased the max number line allowed by Grbl to 9999999 from the
g-code standard 99999. The latter seems to be an arbitrary number, so
we are allowing larger ones for at least one known use case scenario.
- Created a new test directory to contain some testing g-code to proof
the firmware. Only got started with one test case so far. More will be
inserted as needed.
- Some other commenting updates to clarify certain aspects of the code.
