use getId() instead of getUserName() where user is supposed to be neither Anonyous User nor System Processes.

so that getId() is used for ERP5 users and getUserName() is used for special users
like Anonyous User or System Processes whose id is None.

Allows being compatible with future, improved PAS plugin features.
Also, drop a few useless imports.

In ERP5User, getId() is the identifier, but for SpeicalUser, like
Anonymous User, System Processes etc., getId() is None.

otherwise self._person_value's path becomes like /erp5/acl_users/1
instead of /erp5/person_module/1.

Add methods to retrieve the user and login documents using PAS API.

For forward compatibility with multi-login, login-change,
login-is-not-id improvements.

This API is deprecated.

on cmdline, stderr and stdout fields.

With old versions of Zope, it was possible to define the SMTP connection
timeout but this is not possible anymore even though MailHost, in turn
using zope.sendmail, uses Python smtplib library.

This meant that once connect() was called, it may have taken around 2
minutes or more before timeout (and this is OS-specific as well)
blocking one Zope thread.

mostly for erp5_bank_reconciliation and trade

removing lines, columns and tabs but improving PaySheetLine_asCellRange

These methods were generated when rendering the ListBox and with the id
of the ListBox in their name. However, a customer reported the following
problem on Accounting Periods ListBox:

  1. Display Accounting Period ListBox on ZEO-1.
       => The ListBox will be rendered and 'listbox_period_list_*' methods will be generated on ZEO-1.
  2.  Click on 'Next Page' button and the user is redirect to ZEO-2 where the ListBox has never been generated.
       => The method does not exist yet and thus a 404 error is raised.

Instead of having one method per ListBox ID, only one is now created (eg
listbox_setPage() for SelectionTool.setPage()) at Zope startup and the
ListBox ID previously defined in the method name is now defined in the
value attributes of the buttons.

Pattern: SIT_1 => RSPL => SIT_1.

Also, this reduces the complexity by not checking objects twice.

Functional Tests: Migration to PDF.js in recent Firefox clears preference to save automatically PDF files to the disk.