add Paths

[rors]

@rors will break this up into several separate issues:

• add a Path field to the Event model in the Django admin
• add this to the API somehow (depending on Darius's needs)
• render path on map
• timeline filter path objects based on which event they are attached to

[rors]

@simgan the data entry interface for this is working. You should be able to edit any event and manually draw in a path. The user interface is not ideal. Let me know if you have questions about how to use it.

This has not been added to the API or Leaflet yet, so it will not show up in the front-end. Still working on that. But you can get started on the data entry now if you'd like -- i.e., if you enter anything at this point, it will not get deleted.

[simgan]

@rors @radius I added the paths in the Django data entry.

[rors]

done!