Gravatars

This adds [Gravatars](http://www.gravatar.com) around the members area.

Gravatar additions in:

- People (page restyled to be grid of pictures with names and roles, see screenshot)
- Member page
- Applications (very similar to people page)
- Single application page
- Account settings

People page screenshot:

![people](https://cloud.githubusercontent.com/assets/1116815/3560004/5d16c2ac-0956-11e4-9ee7-d75d9e08f327.png)

Applications page screenshot:
![applications](https://cloud.githubusercontent.com/assets/1116815/3560003/5d12cf30-0956-11e4-85ee-0a910b7d7ddb.png)