Before updating with an "unuse" event any of the items of an order,
in the specific case that it is a tube rack, we'll let the rack
perform a preprocessing step of the update object. This update object
will be filtered by removing any reference to the actual rack with the
order for a role if it contains still tubes that belongs to another order
and this tubes are still in the status "done". This means that we will not
be able to "unuse" a rack if it still contains usable tubes.
Added configuration list of roles to check in the validation as we only
want this change to take place on reracking stage (samples.rack.stock...)
Merge pull request #131 from emrojo/unuse-event-tube-rack-handling

Unuse event tube rack handling