Added Makefile for building event system.

event/Makefile

+# Makefile for building event system
+#
+# $Id: Makefile,v 1.1 2001-11-01 18:48:50 imurdock Exp $
+
+subdirs = lib sched test
+
+default clean:
+	for dir in $(subdirs); \
+	do \
+		( cd $$dir && make $@ ); \
+	done