add CommentTotalWordCount queue class
add redis DataCache class, and attach to the CommentTotalWordCount queue
call Resque worker for comment_total_word_count after comment creation on CommentsController#create, pulling its value on the DashboardController#index
push the calculations back down to the model, now the controller has no idea of the implementation (which is what we want)
add worker tasks and caching for article_total_word_count