on specific accounts on closed periods.

Remove unnecessary conditions related to invoices

in account.move model

This commit consolidates the logic for updating date fields in the
`account.move` model into a single private method `_update_dates`.

Docstrings

only if a fiscal year of same code exists for the same company. The exclusion
must be executed on the basis of the company and not without it.

On call of the 'find' methods of fiscal years and accounting periods, ensure
that only one object is returned.

to specify a keyword argument, which will define the codes of the periods to
create.

a recordset, and not only one record at once.

obsoleted by accounting date this module adds.

Upgraded the module version.
Updated the change log.

based on menu items.

Specifics to play better with accounting changes:

* No longer change the base ``date`` field; add ``accounting_date`` instead.
* Build periods when loading accounting data for a new company.

 in tests, copy an existing product rather than creating a new one to avoid problems with new required fields in other modules
and also  remove description from manifest as README.rst will be used automatically instead