Topic/enhance event lists

I think not having the URL regex or name here reduces readability, and is not worth the DRYness.

Consider removing the `.url()`, `.url_pattern()`, and `.url_name()` methods from `EventList`, and replacing this section with:
```python
url(r'^user-events/$', immediate_events.endpoint(), name='user_events'),

url(r'^all-events/$', all_events.endpoint(), name='all_events'),
```