closes #224

make ALL attached folders are returned

for #248, needed to run rake blacklight:install:migrations in order to get a new migration for bl 5.4.x series

clean up cat/subject bug. Closes #250

clean up view code with pluralize method, close issue #249.
Merge pull request #254 from pulibrary/bugfixes_hydra_7_upgrade

closes #224
Merge pull request #255 from pulibrary/development

Hydra 7/BL 5 Bugfixes