Everything *before* the accounting_day day of the month will be delivered.

Allow to pass accounting_date in params in order to easy testing (otherwise
DateTime object would have to be mocked up).

The script disallows to choose day bigger then 28.

internal_packing_list_module and purchase_packing_list_module are available on
site.

This portal type is not used anymore.

This portal type is not used anymore.

The SlapOS code gained full accounting functionality.

Yep, Luke is nice again for live test system.

Also provide test skeleton.

Funny, portal type have to be configured in project BT5.

This will be no-op in case of divergence testers which are not automatic, and
is required again as invoice and transaction lines are merged.

SPLs does not share root applied rule.

Its total price related with use/trade/sale shall match related packing list
total price.

SPLs does not share root applied rule.

SPLs can have more lines which shall end up in same invoice.

Nonetheless SPLs have only one resource, so there is no need to merge them on
invoice.

hosting_subscription is not needed.

Also update rule to allow automatic solving.

Sale Packing List and Sale Invoice Transaction which are specialised by
getPreferredAggregatedSaleTradeCondition shall be managed in same way.