slapos_subscription_request: no need to call OpenSaleOrder_updatePeriod when creating the open order

If the open order does not start the same day, do not ask user to pay for those missing days

subscription periodicity

Set it directly from the script which create it

No idea if it is a good idea or not for now

Previous movement group already force the same invoice

Do not search with a None value

slapos_subscription_request: do not accept new services if the virtual master subscription state is not expected

It is too early, and prevent other Simulation Movement to be aggregated

Speed up execution of the simulation process by triggering alarms as soon as it is needed

Generate invoice from packing list

XXX no way currently to support having no destination if the destination_section does not handle accounting