allow plugs to use 'each' to convert one resource's backlink into a set of resources of another type
was using class name for lookup, changed to typeUri
fixed Utils.isCloneOf, Cache.cacheResource to only cache when the resource has a uri
photogrid for Intersection, Handler, FriendApp and Friend
reverted change to Backbone.sync override that made it return a jquery promise object, ironically it ended up only complicating things