Fixed RegForm Field File rendering when null
Fixed registration from binding with user data

* ng-init was wrongly used
* Fixed all the double binding for the form fields and sections. The form was not being filled with info from the registrant, when the user data (ajax request) took longer.
* Some form validation was not working (e.g. sessions 2 priorities)
* Cancelled social events were not displayed for old events (cancelled value for old events = 'old', new events = 'true')