anchor.diff:      slot.id = null
       slot.is_reserved = false
       slot.can_modify = false
  +    slot.offered = false
       updateCalendar()
   
   
  
positive.code:   ## Global config: message to the end user concerning the subscriptions rules
    $scope.subscriptionExplicationsAlert = settingsPromise.subscription_explications_alert
  
    ## Gloabl config: message to the end user concerning the machine bookings
    $scope.machineExplicationsAlert = settingsPromise.machine_explications_alert
  
  
  
negative.code:   ## the moment when the plan selection changed for the last time, used to trigger changes in the cart
    $scope.planSelectionTime = null
  
    ## mapping of fullCalendar events.
    $scope.events =
      reserved: [] # Slots that the user wants to book
      modifiable: null # Slot that the user wants to change
      placable: null # Destination slot for the change
      paid: [] # Slots that were just booked by the user (transaction ok)
      moved: null # Slots that were just moved by the user (change done) -> {newSlot:* oldSlot: *}
  
    ## the moment when the slot selection changed for the last time, used to trigger changes in the cart
    $scope.selectionTime = null
  