Create ArchivesLinks

Combine the separate junction tables between links and works,
exhibitions, and publications.
Test ArchivesLinks save filter with url
Remove old refs to hasMany Exhibitions and Publications links
Show archives links in exhibition partial if they are set
Add Link helper
Let link helper identify youtube urls
Allow Link helper to identify vimeo host
Show different icon for video links
Don't use elision in link caption
Leverage html helper
Allow attaching publication to album
Create partial for albums archives editing
Create partial for exhibition archives editing
Move links partial
Show albums in publication view
Show publications in album view
Show publications in album pdf view
Look up album publications and send to pdf view
Refactor package add function

Look up an album, its documents, publications, and works; and save all
published documents in one go to the ZIP file.
Add comment about getting an artwork's caption for a document