Make it clear that we should use not callout_stop but callout_halt before callout_destroy
This now needs clock.h
provide forward declaration for struct timeval;
this needs clock.h
this is supposed to be SECS_PER_DAY.
bcdtobin and bintobcd are now inlines in <dev/clock_subr.h>
kill the macros that called the inlines bcdtobin and bintobcd and define
them directly here.
use the inline bcdtobin and bintobcd directly instead through a macro.