Add models and UI elements to support new Serrano stats endpoint

Fix #673.

The new workspace page looks like this(screenshot take from OpenMRS demo):

![screen shot 2014-10-14 at 1 42 46 pm](https://cloud.githubusercontent.com/assets/3911912/4633718/c6293d7a-53c9-11e4-99ed-e8b469eac63c.png)