Update shopping carts controller to pass Solr Documents and to retrieve duplicates of core record objects, which will fix the issue w. multiple content objects for the same core record in one download showing up but is also kind of gross.
Remove unneeded variable assignments.
Items in the download list now are labeled as their actual content type (Small/Medium/Large/Master Image, Text, PDF...) rather than always reporting they are the content type of the canonical object associated with the core record they're attached to.