New plugin manager half-implemented. Most of the UI/frontend code is done. Moved sql_parse.php to /includes/ to allow use after installation - TODO: check installer, etc. for breakage
-- This is really honestly a better way to handle plugins.
CREATE TABLE {{TABLE_PREFIX}}plugins (
plugin_id SERIAL,
plugin_filename varchar(63),
plugin_flags int,
plugin_version varchar(16),
PRIMARY KEY ( plugin_id )
);