Updated migraine actions (create/edit)

New
- Added RequiredIf validationAttribute
- Added StillHappening checkbox and bound end-time to
RequiredIf(!StillHappening)
- Migraines are now passed in as view models to the create/edit actions

Updates
- Began reformatting migraine views with table structure instead of
stacked layout

Fixes
- Resolved all but one bundle issue
- Calendar now displays (doesn't do anything yet)