Add ability to filter project observations by location

[mo-nathan]

As a user viewing a project, I should be able to filter the names based on relevant locations so I can share such lists with land owners/managers.

[JoeCohen]

How about this:

• Project has_many Locations (and probably vice versa) - easy
• Fix Show Names link on Observations index pages - probably hard

Use PatternSearch, IF a Project had many Locations. We could use the earliest-created Location as the Project's overall Location.
The UI could be something like:

• The Project page has a Locations button, similar to other buttons
• The button goes to a projects location page, which: lists Locations (each linked to the Location); has an Observations button per Location which button incudes an Observation count;
• That Observation button does a Pattern Search
• Click Show Names link (currently broken -- it shows all Names in the db) on the resulting Matching Observations page