Add a tutorial for advanced Open vSwitch features.

Signed-off-by: Ben Pfaff <blp@nicira.com>

tutorial/t-setup

@@ -0,0 +1,8 @@
+#! /bin/sh -ve
+
+ovs-vsctl add-br br0 -- set Bridge br0 fail-mode=secure
+
+for i in 1 2 3 4; do
+    ovs-vsctl add-port br0 p$i -- set Interface p$i ofport_request=$i
+    ovs-ofctl mod-port br0 p$i up
+done