Issue: Store Creator on the Page Node

Currently the username, userid, ipaddress is stored on the revisions, which is fine except when we need the creator of the page (if only the creator can edit, or in the contributor list). Instead of adding an extra query for all of this, it's best to have database fields for this on Page and Attach nodes.

Also, other node types should have username and ipaddress fields in case guests have permission to create them.