Allow edition in the new UI

This make everything slow as hell and prevent to quickly save.

Example: <h2 class="foo">bar</h2> => <h3 class="foo">bar</h3>

erp5_web_renderjs_ui: keep previous focus color

* update template tool configuration
* create working copy
* create skin folder
* throw away local changes

Add a gadget to display and select the list of changes.

The gadget will show the selected diff to change the selection if needed.

Changelog can also be directly entered in the gadget to quickly switch the view while writing it.

Use usual ERP5 page template to commit bt5 changes from ERP5.

Use an hidden field to propagate all needed input values in case of an exception.
This single field will keep a json value, to simplify the maintainance of all forms using it (instead of many string fields).

Stop accessing the REQUEST directly, and rely on ERP5 navigation scripts (like Base_redirect) instead.

See nexedi/erp5@ea219b74

If enabled, accessing the 'View' skin selection will raise an Error.

2 alarms are provided to automatically enable/disable xhtml style for some period of time.

Some users can be always continue using xhtml style.

See nexedi/erp5@d7a4c3fc

Fixes #20200630-BB32 and #20200630-48F9FA

See merge request !1318

in c361a8c3 (erp5_pdm: improve product invividual variation, 2020-03-09)
we changed to allow default images in product individual variation and modified
IndividualVariation_view to add a file upload field to upload an image, but this
form is shared with other individual variations portal types.

Without setting the default image property sheet and allowing Embedded Files as
sub-documents, saving the form was causing an error.

Possible services depend on the selected project.

If we only refresh this list when user selects another project, we don't
support the case where there's only one project available for user, because
the list of services is the default one, not the one filtered for the
select project.

Now that we have an empty item, we should make sure user selects something.

If we have more than two options to project and resource

RSVP.Promise cancel callback do not expect a Promise as result.
In order to handle potential errors triggered by setButtonTitle, run it in an renderjs's job.

See merge request !1285

We no longer run tests with `python setup.py`, but simply with `python -m unittest`

With slapos!862 we no longer need this

See merge request !1316

See also https://github.com/zopefoundation/ZEO/pull/63
     and !1095

No error in testCMFActivity and testConflictResolution.
For the only error in testInvalidationBug, see comment.

But this commit is not enough for ZODB5. The only known issue so far
is the use of newer pickle protocol, which breaks export of ZODB data
and requires non-trivial changes in our XMLExportImport/ppml code.
So for the moment, many failures in testBusinessTempate.