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
11 files changed