To be able to use pre_upgrade we would need to install the bt first

As Pay Sheet Lines, Pay Sheet Transaction Lines and Annotation Lines
have been made generic using the Invoice Line class

As Pay Sheet Line has now Invoice Line as base class

Because of ERP5Type.UnrestrictedMethod, 'System Processes' can own objects.
Such objects can be proxy-role'd scripts, and proxy-role mechanism
triggers many users look-ups (each time security is evaluated, which is
virtually every getattr). Each such lookup will do a query for 'System
Processes' user, which will (hopefully) find nothing anyway.
So special-case 'System Processes' when looking by user_id by skipping
the search altogether (enforcing the inability to locate this user,
consistently with Zope assumptions, and consistently with previous
behaviour).

The code was not working as expected when we had several test nodes with same name
(which should not happen). So add a timestamp in the title.

test_result: fixed random issues where test result was staying confirmed while all tests were finished

When two test results line were stopped in parallel, both transactions were thinking that
there was still one ongoing test line, thus none of them were setting the test result in stopped.

Use activities instead of serialization to avoid having testnode getting conflict errors.

This makes a difference for SQLDict as not all messages are accepted for
insertion.

Firefox and Xvfb aren not provided by the tested SR,
but rather by a separate SR that is installed by the testnode.

Charting libraries are better within iframe to avoid enabling too permissive
Content Security Policy globally

Fix error display after save
Fix parameters not recognized
Fix python linting
the same way as ERP5 Script Python

Add PortalType field to distinguish different types of Python Scripts, add referencence and use source code editor

We could not find a portable way to use verifyElementPositionRangeTop.

See internal discussion `[test][erp5] update selenium test` for more
details.

In addition to TypeEror when a 'date' is given, this also accepts duration=0.