Add a user profile view

Adds ``/~username/`` to serve as a profile url for users. Includes user accounts, and package roles to support this use.


Preview of the ugly first draft:

![image 2013 10 29 3_46_57 am](https://f.cloud.github.com/assets/145979/1426517/abf3c444-406e-11e3-98fd-ee954bcac1f0.png)