Added DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses to the timestamp column definitions, just in case those aren't the default settings in the MySQL server.   See SF Support Requests #605

git-svn-id: http://svn.code.sf.net/p/mrbs/code/mrbs/trunk@2872 25f7e783-145e-4f2d-a9f8-dd7182bfe9c7