Added server-side code to create host-to-host intent. Still WIP.

Change-Id: I80626aa9ecb38802ddca4be3bce3def85ccfdb88
diff --git a/web/gui/src/main/webapp/topo2.css b/web/gui/src/main/webapp/topo2.css
index 2602f6f..a5bf661 100644
--- a/web/gui/src/main/webapp/topo2.css
+++ b/web/gui/src/main/webapp/topo2.css
@@ -71,6 +71,11 @@
     opacity: .7;
 }
 
+#topo svg .link.showPath {
+    stroke: #f00;
+    stroke-width: 4px;
+}
+
 /* for debugging */
 #topo svg .node circle.debug {
     fill: white;