Requests for comment/Native geospatial data types

Background
The GeoData extension is deployed in mediawiki sites and its API is widely used by the community to hyperlocalize knowledge. It currently stores geospatial data using int/float MySQL datatypes, rather than native spatial data types.

Proposal (in general)

 * GeoData as it is, already requires MySQL 5. MySQL 5 supports spatial datatypes anyway, why not use them instead?
 * Using spatial datatypes will allow us to take advantage of more advanced spatial functions (e.g. within, touches, etc.)
 * A lot of knowledge stored in mediawikis are geospatial by nature.