[FIX] Send proper Content-Type in headers
[IMP] API error handling
[IMP] RegForm: post registration page style
[IMP] RegForm: post registration skips labels
[IMP] RegForm: post-reg page payment box style
[IMP] RegForm: post-reg page price display

* Price is now only displayed in payment summary box
[IMP] RegForm: post-reg page e-ticket button

* Better integration with new style
[IMP] RegForm: post-reg page typos en cleanup
[IMP] RegForm: post-reg page reword of message
[IMP] SASS i-button highlight style

* Better coloring and added :active effect
[IMP] RegForm: post-reg page payment table style

* Ensures no wraping of price when item name is too long
[MIN] RegForm: post-reg page checkout button width
[FIX] RegForm: post-reg page payment box display

* Payment summary box was always shown regardles of having any content
[IMP] Show warning if no currency
[IMP] RegForm: Show closed if no currency selected
[FIX] RegForm: Overlap arrival and departure dates
[FIX] RegForm: disabled sessions shown as options
[FIX] RegForm: Sessions fetching on dialog update
[FIX] RegForm: number field not showing price
[FIX] RegForm: Radio items disaabled at creation