provide custom ATTicketCartItemDataProvider for a cart item title to include event information
fix TicketOccurrenceDataProvider to not proxy the parent overall, but correctly return title and id and get the rest from its parent. fix create_bookings to not create them from self.context (we^re in a placeless adapter here) but from the booking items.
rename to ticketoccurrencecartitemdataprovider
Merge pull request #3 from bluedynamics/thet

TicketCartItemDataProvider + create_bookings fix