merge from experimental branch
remove extra stuff unrelated to GPS, merge the power changes
add a function for converting the gps timestamp to standard time.h format that can be used with the RTC
raise event flag on fix
merge GPS improvements from my experimental branch
merge the status access functions
Merge branch 'chibios_gps' of https://github.com/rambo/ruuvitracker_fw into rambo-chibios_gps

Conflicts:
	main.c
Merge branch 'rambo-chibios_gps' into chibios