Dev

Let MySQL use the INFORMATION_SCHEMA the same as the other databases.
Retrieve the foreign key table & key.
Extend get to optionally dereference the foreign key and retrieve a new Mapper object with the object(s) in the foreign table.

NB: I believe MySQL 5.0 and newer supports the INFORMATION_SCHEMA. If older versions need to be supported, the ATTR_SERVER_VERSION (from version()) could be used and a new engine_subtype created in \DB\SQL which lets the schema() function treat older MySQL databases using the SHOW columns method.