Updated the discount actions for Form.

- Added the database column in a more appropriate manner.
- Updated the logic for pretty fields on the front-end.
- Also updated some of the javascript to smooth out the form actions,
  and passed in the state variable to handle multiple states.

Next to do:
- If cat_event_user has been set by admin for discount do NOT show it in
  the taken categories until that user has accepted that discount and
  hit that category on their form.
- Show the user that logs in with discount that admin has applied that
  there is a discount available for them to use.
- Once a user hits submit and accepts and PAYS for that booth under
  discount then call that discount 'taken' on the form.  Double check
  this workflow on production.