SEQUENCEs and NO MAXVALUE NO MINVALUE

Adds in NO MAXVALUE and NO MINVALUE options for create sequence per 200X
spec, which will also make alter sequence a touch easier.

sequence.c  init_params() will check for settings which have been
defined twice, and complain.

--
Rod Taylor <rbt@rbt.ca>

PGP Key: http://www.rbt.ca/rbtpub.asc