Split off AvailabilityDAO from CarDAO
List of cars for a given user no longer contains duplicates
Refactored availability code - step 1
Cleaned some code
Refactored availability code - step 2 (uses seconds in week instead of seperate day/time of day)
Refactored car picker to use listCars
Availability becomes 'when *not* available'
Another major cleaning of car related code
Added some filter code to getCarList
Cleaned job and scheduler code