Remove the IdNotFoundError from the project entirely.  ActiveFedora's provided ObjectNotFoundError is more than adequate.  Not sure why I ever implemented the other thing.
Refactor the editable_objects controller to always throw a ParentNotFoundError when that is the problem.
Update core file controller to use the object_404 template.  Leave the other 404 template in just in case it's important.
Add object_404 error to community and collection controller.
Add basic tests for special 404 functionality.
Merge pull request #122 from nu-lts/feature/tombstones

Feature/tombstones
Add appropriately filtered destroy action to collections.
Tweak the delete_object helper to also take a second string arg for label text.  CLean up rendering of some stuff on the shared show sets page.
Destroy action now defined in our controller.
Comments out a line that was breaking the edit form.  Note that we weren't setting permissions for files anyhow.
Test updates
Unbreaks edit/update a little bit.  These are still pretty broken tho.
Skip the load and authorize resource hook for destroy action.  Now it works.
Merge pull request #123 from nu-lts/feature/destroy_things

Feature/destroy things
Add three methods for pulling only children objects that the currently authenticated user can read.  Move some shared code into the less confusing SetsHelper, instead of just using it from NuCollectionsHelper.  Include SetsHelper for the collection and community controllers.
Move current_user_can read/edit? methods out of application_helper and into application_controller, where they belong.
Refactor helper methods for filtering children objects into set controllers, make collection/community controllers subclasses off that.
Merge branch 'develop' into feature/set_helpers

Conflicts:
	app/controllers/communities_controller.rb

Accidentally made a few commits directly onto develop.
Fixing up some changes lost in the merge.
remove reference to sets_helper in nu collection controller.