Changed all header guards so they will not use unserscores as pre- and postfix.
PowerManagement: Introduced a configuration (board.h) to select the attached sensor ring module.
updated all file headers to 2019
Added some basics to mask pads during GPIO initialization (wip)
Doxygen file documentation and modules.
Introduced SSSP stage 3 of the startup phase (module stack initialization).
moved the /os/modles directory to /modules