Support Multiple SQL Dialects #102
Description
We are looking to support SQLite3 and PostgreSQL in addition to MySQL. I would like to accomplish this by refitting the MySQL Directory and Authentication backends to be more generically named SQL (ie. SQL_HOST, SQL_USER, SQL_DATABASE, SQL_PASSWORD, SQL_SCHEMA etc). We then need an abstraction layer to select the right database driver for the configured SQL_DRIVER. The user could then supply the required SQL queries as additional configuration parameters.