daemon: test restarting.

We add a "dev-restart" command which causes the daemon to close fds
and exec itself.  Then we do it after every command, with the caveat
that we always send a commit before newhtlc, because if not committed,
that is forgotten.  Fulfillhtlc and failhtlc get resent, since they're
idempotent.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/opt_time.c

@@ -77,3 +77,22 @@ void opt_show_time(char buf[OPT_SHOW_LEN], const struct timerel *t)
 	} else
 		sprintf(buf, "%lus", t->ts.tv_sec);
 }
+
+char *opt_set_timeabs(const char *arg, struct timeabs *t)
+{
+	long double d;
+
+	if (sscanf(arg, "%Lf", &d) != 1)
+		return tal_fmt(NULL, "'%s' is not a time", arg);
+	t->ts.tv_sec = d;
+	t->ts.tv_nsec = (d - t->ts.tv_sec) * 1000000000;
+	return NULL;
+}
+
+void opt_show_timeabs(char buf[OPT_SHOW_LEN], const struct timeabs *t)
+{
+	long double d = t->ts.tv_sec;
+	d = d * 1000000000 + t->ts.tv_nsec;
+
+	sprintf(buf, "%.9Lf", d);
+}