Add functionality to search by an artist's location.

[afikanyati]

This task is complete when a location can be entered (such as 'boston') in the search manager, and results returned will only be from artists matching this location.

[afikanyati]

Location can be specified as City, Country. This will require an input change in the artist portal along with the curator portal.

[slivingston]

I discussed this feature with @Naomish12 today, and we arrived at there being at least three kinds of location that should be supported:

1. current or past city where the artist has worked; e.g., a "Boston local" artist who can visit the gallery on opening night, but who is not necessarily currently living in Boston.
2. one or more locations that provide basic influence and inspiration for the artist, independently of the artist's current geographical location.
3. labels about the artwork itself; e.g., the drawing is of a sunset over Boston.