Initial prototype of LTI integration
Add missing ME gem; fix typo in example config
Adding LTI initializer
Quick refactor of lti authn so it doesn't conflict with normal authn providers
Add 'add class' button to limit access option
Add virtual groups to user model
Use #visibility and move exceptions into new elements instead of access element; Hook up controllers; fix bug with updating groups
Added virtual group facet
Virtual groups persisted in the session; class facet added
Handle case when current_user is nil
Automatically apply class facet with first virtual group
Add class link to navbar
Handle nil current_user
Silence constant redefinition warnings
Add tests
Move Class facet into admin facet group
Merge pull request #224 from avalonmediasystem/feature/lti

LTI support (VOV-2233)