Adding setborderpx patch

patch/setborderpx.c

@@ -0,0 +1,20 @@
+void
+setborderpx(const Arg *arg)
+{
+	Client *c;
+
+	if (arg->i == 0)
+		mons->borderpx = borderpx;
+	else if (mons->borderpx + arg->i < 0)
+		mons->borderpx = 0;
+	else
+		mons->borderpx += arg->i;
+
+	for (c = mons->clients; c; c = c->next)
+		if (c->bw + arg->i < 0)
+			c->bw = mons->borderpx = 0;
+		else
+			c->bw = mons->borderpx;
+
+	arrange(selmon);
+}