add bootstrap dashboard that picks up added sites

Upgrades the default dashboard to:

 - Look in the /srv/www folder for added sites and list them alongside the defaults
 - Descriptions of built in tools
 - A link to the documentation wiki
 - Bootstrap 3 styling

![screen shot 2014-04-20 at 21 46 11](https://cloud.githubusercontent.com/assets/58855/2751423/fe06fe54-c8cc-11e3-857f-f5f19aa78534.png)