added layoutmenu patch

patch/bar_layoutmenu.c

@@ -0,0 +1,18 @@
+void
+layoutmenu(const Arg *arg) {
+	FILE *p;
+	char c[3], *s;
+	int i;
+
+	if (!(p = popen(layoutmenu_cmd, "r")))
+		 return;
+	s = fgets(c, sizeof(c), p);
+	pclose(p);
+
+	if (!s || *s == '\0' || c == '\0')
+		 return;
+
+	i = atoi(c);
+	setlayout(&((Arg) { .v = &layouts[i] }));
+}
+