Implemented synchronization message output for NanoDLP printers (nanodlp.com).
If optional feature is enabled in `Configuration_adv.h`, Marlin will ouput "Z_move_comp" string to serial after completing any G0/G1 Z-axis movements. This feature patched on previous versions(1.0) is used by NanoDLP to synchronize Z-axis movement with projector exposure in DLP stereolithography printers.

* Fix thermal protection documentation.

Even before the recent thermal protection changes, the documentation of
the thermal protection feature in the config files did not match the
implementation.  I fixed the documentation and reconciled the M303
implementation with the documentation.

* Applied documentation changes to sample config files

* Renamed hysteresis to watch_temp_increase

* Added gcodes back into documentation.

* Initial conflict resolution

All previous items resolved:
- Use of ELAPSED() on timer code
- Switch to use of defer_return_to_status=true as much as possible
- Update & Clean Up of Max7219 routines

* Resolve non-SD case in ultralcd.cpp

Based on #7637 by @marcio-ao

Ideally, it should be calculated based on Z steps per unit so that each
babystep corresponds to around 0.025mm. Smaller than this is largely
insignificant for typical layer heights.

* Add MAX7219_DEBUG to Travis CI testing

* Tweak config and use standard pin naming for MAX7219_DEBUG

* MAX7219: Apply coding standards, use macros, etc.

* Make code work...

Add a parameter to enable/disable audible user script feedback

Add more details as requested in #7198

Sends pre-defined string as action command when printer is kill.