Commenting updates. Minor bug fix with exit of soft limit event.
Merge pull request #356 from robgrz/dev

Line number reporting as compile-time option.
Minor updates to line number feature.

- Changed line number integer types from unsigned to signed int32.
G-code mandates values cannot exceed 99999. Negative values can be used
to indicate certain modes.

- Homing cycle line number changed to -1, as an indicator.

- Fixed a reporting define for the spindle states that was broken by
the last merge.