BUGFIX: we were writing invalid STI types...
Render the links when we have more than 1 group
Previous logic rendered if we had more than 0 groups
Something is getting done
Assert correct event_id's on thrash and ungroup groups
BUGFIX: associated groups didn't have correct event_id after create
Initial testing for to_hash
Link presentations to events
Only list presentations in current event
Only show presentations from current event in the select field