This fixes a bug with overlapping sticky keys when the same key
positions on multiple layers contain different sticky keys.
This also fixes the case when a MT has a sticky key for hold and a
different sticky key for the tap behavior.
Fixes#508
Aligns *.h and *.c to underscore naming convention.
These were kept (with warnings) for backwards compatibility with external boards/shields:
- kscan-mock.h
- matrix-transform.h
They should be removed in the future.
PR: #523