Wrong DB Type make install fall when using SQLite

On module activation when using sqlite as db storage, the module fails to install. Issue is that item_id is defined as serial, while the primary key for the table is array('item_id', 'tag'), which leads sqlite to just mess up during the table creation.

Schema for the 'advancedqueue_tags' table seems to be wrong as 'item_id' should be defined as 'int' rather than 'serial' (since it's somewhat a foreign key).