Adds full metadata editing for Collections (same DC fields as GenericFiles)

Fixes hydra-editor style partials in views/records.

refs gwu-libraries/gw-sufia#82
refs gwu-libraries/gw-sufia#25
If this partial is used for both Collections and GenericFiles, and the former looks for creator in properties and the latter looks in desc_metadata, how will this work?  The partials in records/show_fields/ seem to be inconsistent on whether they point at the props ds or the descMD ds.  Is this intentional?