Following features are added.

1) Show VMs if any, on click of vrouter
2) Pan, zoom are corrected.
3) If URL has other query params except what is required to draw topology, no additional ajax is sent.
4) Partial implementation of Trace flow.
5) Post data on search flow includes 'where' clause data.
6) clicking on link between prouters/vrouters populates 'Details' tab with interface information.
7) clicking on prouter, shows basic information on 'Details' tab.
Merge pull request #5 from rajreddy/webui

Following features are added.