#232 adds CustomCollections resource for activeadmin
wip
#232 Allow admins to manage custom collection collaborators
Merge branch 'development' into admin

Conflicts:
	app/models/custom_collection.rb
#232 collaboratos can add/remove items from customcollections.
For #232 Tests Collaborators adding to collection

Tests to ensure authenticated users who are collaborators on custom
collections can successfully add items to those collections. Also fixes
previously unidentified issue in activeadmin where creating a new
customcollection in the admin interface wasn't working because the owner
type wasn't being properly set.
#232 remove save_and_open_page
Merge pull request #297 from afred/admin

Admin