* Add easier macros for conditional polling/interrupt code.
* Properly continue polling on intervals, without extra
enable/disable code for pins that is superfluous when not trying to
deal with interupts firing.
* Fix to allow multiple GPIO drivers when doing splits w/ IO expanders
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