Google Cloud SQL modifications for MySQLi

Not ready for final commit, I am passing this through style and unit test checkers.

Initial pass on a Google Cloud SQL driver for mysqli.
https://developers.google.com/appengine/docs/php/cloud-sql/

Google Cloud SQL is /almost/ identical mysqli - needs some slight changes in order to connect from within a Google App Engine app to handle their socket string format - and it needs some coding logic in the connect statement in order to ensure the correct connection information is used[socket when running on GAE, host/port when running externally]