Added joda time dependencies
Added joda datetime column type
#83 Adapt datetime json serializer
#83 Substituted date4j imports
#83 Adapted DateTime QueryStringBindable
#83 Improved optional bounds (from, to) handling in GET /appointments
#83 Fixed json formatters
#83 Removed java.util.Timezone import
#83 Fix date string format in AdministrationService
#83 Adapted free time slot algorithm
#83 Adapted conflict algorithm
#83 Use offset of milliseconds from UTC for QueryStringBindable[DateTimeZone]
Use UTC in DateTime json serialization
#83 daysBetween's lower bound is now inclusive
#83 Fix DateTime difference calculation
#83 Adapted findFreeTimeSlots