Add a blank column for virtual folders if the user can manage them.
Merge branch 'lessonbin' of github.com:fuzzie360/coursemology.org into lessonbin
Ensure that users can only see the workbin for missions and trainings they can access.
Merge branch 'lessonbin' of github.com:fuzzie360/coursemology.org into lessonbin
Possible fix for mission files appearing in workbin when they shouldn't.
Merge branch 'lessonbin' of github.com:fuzzie360/coursemology.org into deployment

Conflicts:
	app/models/course.rb