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
* Allows "gaps" for keyboards like Kyra.
* Allows keyboards with matrixes that don't map the logical key
locations to have normal looking keymaps when defined.
innovaker