Reconsider stock period check

Since changeset 4d228a081908 we no longer set the effective date of a move when it is assigned. However, currently we still check if there’s an assigned move in a period before we allow to close it:

http://hg.tryton.org/modules/stock/file/tip/period.py#l126

I’m thinking that maybe the check is not correct. I see several possibilities but maybe this is the one that convinces me the most:

Check for any move that is not in ‘done’ or ‘cancel’ state and has effective_date set to a date within the period to be closed. If there’s one, we raise a warning (not an error) and let the user decide if she still wants to close the period.

Opinions?

I do not see why modules/stock: 4d228a081908 would make the close_period_assigned_move check invalid. Having a move assigned and planned for withing the closed period should still not be allowed.

It seems to me that we could “relax” the constraint. Still do not allow to set any moves as done within a closed period, but let the user ignore the warning at their expense.