Work in progress, and this now works for the following:

- add/update geo data to an existing tag via the tag edit page of the dashboard
- view existing geo data on a tag when viewing the tag in the tag edit page of the dashboard
- delete geo data when deleting a tag via the dashboard

There is still much to do:

- make geo entry in dashboard convenient
- integrate with WP Query to allow selection of posts based on geo inputs
- create a scriblio facet class to allow easier filtering by geo
- integrate with 3rd party data sources, create specific geo taxonomy with hierarchies from city to state to country
- intergrate with natural language geo extractors to improve geo tagging of content