ERP5 Software Release upgrade test + restart zopes on conf change

Introduce a new "software release upgrade test", which tests a scenario of keating
an ERP5 instance with an old version of software release and then update it to
current version.

To support this test and because we are using this technique for most of slapos
softwares nowadays, configure zopes to restart automatically when their
configuration change.

See merge request nexedi/slapos!875