Support for spatial data types and functions

Last I heard there was not a meaningful way to *replace* a database driver with your own, but you can easily define your own driver as an extension of the existing one(s) and add whatever you want to it. Then in your database Config just select the new driver:

'DBDriver' => 'SpatialMySQL'

Also check out @kenjis Pull Request for RawSql support because it is possible that will allow you to do spatial handling without a separate driver.