Use Square field per https://github.com/DoSomething/dosomething/pull/3499#discussion_r20665307
Adds paraneue_dosomething_get_campaign_gallery and uses in campaign_group node tpl
Handles unpublished campaign tiles
Fixes pattern function namespace, uses classes_array instead of string
Fixes unpublished class name
Refs #3265 - Only add featured class when 5 or more items
Merge pull request #3504 from aaronschachter/group_gallery

Use mosaic gallery tpl for Campaign Group