src: use bool for true/false members of bitfield struct
time/alarm: add explanatory note to alarm_stop
io/spi: set pull-ups before input mode
button/button: set pullups before input mode
lcd/hd44780: set pullups before input mode
debug/assert: rename assert macro to ASSERT
io/io: rename io_read and io_write macros to IO_READ and IO_WRITE
time/delay: make delay macros uppercase
time/delay: write new, programmable nanosecond delay macro