SiteWideMessages task

@Wikia/platform-team 
Refactoring SWMSendToGroupTask to new job queue. 

Also piggybacking:
Minor refactor to the way tasks can be invoked on Special:Tasks, since there were a few tasks that wanted to live in the Wikia/Tasks namespace, but didn't want to have any methods exposed on the special page.
Updates to FluentSQL: support LIKE clause, fixes to HAVING, and unit tests