Various tweaks to displaying payments
 - Payments are now fetched by a direct call to the Payments endpoint (via $http) instead of using a cache
   - I'm not sure if this is ideal or not, feedback welcome
 - When creating a payment, paymentType 'CREDIT_CARD' is required for processing a CC payment
 - Adding paymentType to paymentsModal
 - Changing label "Transaction" -> "Reference #" in paymentsModal.
   - This could probably use a tooltip for more information
Display totalDue for each registration
Pass into AdminDataCtrl & AdminDetailsCtrl the current permission for the logged in user on this conference.
Display and conditionally allow for update to total due on admin screen
 - Add a directive <total-due>
 - In RegistrationCache add a method to update a Registration and make sure to copy objects when putting them into the cache
 - Add a modal window view and controller for actually updating the total due

WIP, i think this is working, but can't test due to weird redirect loop issue