[move_bewteen_collections] Changes to enable 'move to collection' feature

You might not actually want to merge this into scholarsphere, since the feature is actually aimed more for archivesphere, but either way, this shows what changes you need to make in order to enable the feature in scholarsphere/archivesphere.  Note: this relies on changes in hydra-collections reflected here: https://github.com/projecthydra/hydra-collections/pull/13/commits