Override SolrDocument#initialize to set a field that will return MARC from either the marcxml or marcbib_xml fields.
Move thumbnail controller method into a concern that can be included in multiple places.
Support object specific thumbnail partials to differentiate between catalog and repository items.
Remove alt on cover/stacks images and add a tabindex of -1.
Merge pull request #341 from sul-dlss/stacks-images

Display images from stacks in search results views
Merge pull request #349 from sul-dlss/results-marc

Allow for MARC to be retuned on the search results
Add summary and topics for databases.