Create a system diagram for the website

Originally reported on Google Code with ID 594

```
1) Create a new system diagram
2) Update the research page on wiki
```

Reported by `wbrunette` on 2012-06-06 18:14:11

Locate the research page on the wiki and any existing website architecture material; no repository file or test is named. Confirm the diagram's scope and format with maintainers, create the system diagram, and update the research page so it includes or links to the finished diagram.

Written by the indexing model from the issue text.