r9388: * db-oracle/oracle-api: Add OCIServerVersion

        * db-oracle/oracle-sql: Query and store server version on connect
        * sql/db-interface.lisp: Add new db-type-has-bigint? generic
        function to handle OCI's lack of bigint support
        * test/test-basic.lisp: Separate bigint testing
        * test/test-utils.lisp: Add oracle to specs and list of backends