Copy mapping data from another field

[allanaaa]

Re: #33, and related to Mapping changes currently being developed in S, a bulk-edit feature could be added that allows mapping data to be copied from another field to the Geolocation field.

This would get around the incompatibility between CSV Import and Geolocation; simply import your lat/longs into "Coverage" or some other field, then copy them to Geolocation in a bulk-edit process. We can specify the precise formatting to use in the docs.