REVIEW: Lane pdo connect

First and foremost, this is a performance upgrade. The Database class maintains a constant connection to the local databases rather than continually opening and closing. A large number of the files changed in this pull are simply removing close() function calls on the local databases. I've experienced a noticeable performance bump since changing to this method of connection handling.

Secondarily, I've extended the SQLManager class to include better support for PostgreSQL and PDO. Postgres support is for completeness (I was sick of having it half-implemented) but has not been thoroughly tested. PDO is there to provide an upgrade path when the old "mysql" driver is deprecated. I intend to start rigorously testing it pretty soon. To make this work correctly, I've added a few more abstraction features to SQLManager and removed almost all code-level checks of the "DBMS" setting.