Cleaner installation

Makefile

@@ -1,3 +1,7 @@
+PREFIX=/usr/local
+
+CFLAGS=-I$(PREFIX)/include
+
 EXEC = sumaclust
 
 SUMACLUST_SRC = sumaclust.c \
@@ -41,4 +45,8 @@ clean:
 	rm -f $(SUMACLUST_OBJ)	
 	rm -f $(EXEC)
 	$(MAKE) -C ./sumalibs clean
-			
+
+install: all
+	install -d $(DESTDIR)$(PREFIX)/bin/
+	install -m 755 $(EXEC) $(DESTDIR)$(PREFIX)/bin/
+