[FIX] account: reconcile: no useless revalidation

Avoid revalidating the complete account moves
that contain the lines being reconciled.
The reconciliation does not change the validity
of those moves anyway.
This represents a very important speed up of
reconciliation when moves with several hundred
lines are involved.
[FIX] stock: inventory lines with no production lot: compare with correct stock level

Inventory lines without production lot number should
be compared with the stock level of products without
a production lot. Otherwise the final result of a
validated inventory is wrong as soon as there are
lines with and without production lot for the same
product.

Adds corresponding regression test.

Fixes https://bugs.launchpad.net/openobject-addons/+bug/1008099
Manual rebase of #1658, courtesy of Numerigraphe
[FIX] web: do not focus if the focus_field is not a field

Sometimes, focus_field could be a button, and in such cases, we should not focus on it

opw-612045
[FIX] point_of_sale: field date of report.pos.order should be a datetime

The date_order field of the pos.order is a datetime, not a date
As, in report.pos.order, the date field is related to date_order of the pos.order

We usually do not commit fixes altering the model fields structure in 7.0, but this one is retro-compatible, as the database structure won't change