Add support for reference clocks

Makefile.in

@@ -41,7 +41,7 @@ OBJS = util.o sched.o regress.o local.o \
 	logging.o conf.o cmdmon.o md5.o keys.o \
 	nameserv.o acquire.o manual.o addrfilt.o \
 	cmdparse.o mkdirpp.o rtc.o pktlength.o clientlog.o \
-	broadcast.o
+	broadcast.o refclock.o
 
 EXTRA_OBJS=@EXTRA_OBJECTS@