Add migration to disambiguate between excuse and attendance self submit. Remove unused category field
Update scheme to reflect previous migration
Update events controller params method to handle new fields
Disambiguate between decorator method name and event property of the same name. Update decorater useages to new name. Update event-form to reflect new names of self submit fields
Close #69.Update tests to reflect self submit changes
Add a chairmen seed
Chairmen can only edit events that they're authorized to edit
Update helpers and controller before actions to enfore chairmen only editing event types they own
Refactor events_helper. Add the flash and redirect to the controller before action rather than in the events helper
Update tests for chairman editing event types they own
Fix merge conflicts