by Dave Reid: Removed the 'check for already installed modules' because it happens automatically now.

#610926 by Dave Reid: Added {seo_checklist}.uid to record which user completed each task. Also prettified the interface a little more and corrected non-lowercase {seo_checklist}.module values.

#443506 by tresero, Dave Reid: Fixed the datetime field by combining the option_checked, date_changed, and checked_module columns into {seo_checklist}.completed which stores a UNIX timestamp or 0.

by Dave Reid: Moved a large chunk of the module code into seochecklist.admin.inc so it won't be loaded during every single request.

by Dave Reid: Moved seochecklist.css into the module root directory. It was lonely and now it conforms to core standards.