* add linked list
* macros, and use in buttonshift
* unit_tests macros
* add extern
* add parens
* move extern
* move extern
* move buttonDebounceListHead
* move buttonDebouncePointerHead
* merge gore
* undo
* reduce unused size
* don't store pointer if already initialized
* few changes
* remove oldPin
* fix merge conflict
* merge in changes commited to wrong branch
* fix definition
* out of class?
* brute force programming
* fix few problemos
* am confuse
* am confuse
* am confuse
* am confuse
* oldPin snuck in
* move to public?
* define again
* try constexpr
* def in cpp
* remove constexpr
* fix def
* fix?
* update active
* fix a few things