EFUN: heart_beat_info()

SYNTAX:
mixed *heart_beat_info();

DESCRIPTION:
This efun gives an array of all objects which have a heart_beat running.

RETURN VALUE:
An array of all object with a heart_beat.

SEE ALSO:
set_heart_beat
call_out_info

EXAMPLE:
object *hb_obs;

hb_obs = heart_beat_info();
// hb_obs is now something like
// ({ OBJ("sys/player#1243"), OBJ("sys/player#1533"),
//    OBJ("obj/monster#1149"), OBJ("sys/wiz#1071"),
//    OBJ("sys/player#1428") })
