first pass at ImageReviewTask
add to autoload and enable task
merge origin/dev into jobqueue-imagereviewtask
Merge remote-tracking branch 'origin/dev' into jobqueue-imagereviewtask

Conflicts:
	includes/wikia/tasks/TaskRunner.class.php
run maintenance script directly instead of going through backend/bin/run_maintenance
remove unneeded else statement
removing <insert description here>
STYLING!
Merge remote-tracking branch 'origin/dev' into jobqueue-imagereviewtask

Conflicts:
	includes/wikia/tasks/TaskRunner.class.php
Merge pull request #3902 from Wikia/jobqueue-imagereviewtask

ImageReviewTask migration