GUI -- store ref to node/link selection in backing data.
- tweaking force-layout parameters; now host-to-host intent path is highlighted.
- injectTestEvent() now uses recursion to look for appropriate json files.
- implemented updateHost() event.
- some refactoring cleanup in topo2.js

Change-Id: I888f05032d3c9df6470bd4d2f399f61efb9dbd46
diff --git a/web/gui/src/main/webapp/json/ev/simple/scenario.json b/web/gui/src/main/webapp/json/ev/simple/scenario.json
index d24626f..e320413 100644
--- a/web/gui/src/main/webapp/json/ev/simple/scenario.json
+++ b/web/gui/src/main/webapp/json/ev/simple/scenario.json
@@ -1,6 +1,7 @@
 {
   "comments": [
-    "Add two devices and one link (auto), and two hosts."
+    "Add two devices and one link (auto), and two hosts.",
+    "Then update the two hosts (with IP address labels)."
   ],
   "title": "Simple Startup Scenario",
   "params": {