4003 Show timestamps in inbox

https://code.google.com/p/otwarchive/issues/detail?id=4003

In your inbox, timestamps were not showing up for comments left by logged in users.

Note: The failure on `Scenario: I should receive my own comments in my inbox if I haven't set my preferences to "Turn off copies of your own comments."` might be real. The help text says:

```html
<dt>Turn off copies of your own comments</dt>
<dd>Enable this option if you prefer not to receive emails or inbox notifications for your own comments (for example, when you reply to comments on your own works).</dd>
```

That leads me to believe that I should receive inbox notifications of my own comments if I don't have this setting enabled. However, I cannot seem to make that happen.