[dataimport] Add safety belt on "gen_rtype" in MetaGenerator, closes #3712892 Some cubes may well add to the META_RTYPES set, hence crashing the gen_<somecubemeta> call.

[dataimport] Correctly serialize datetime objects in _create_copyfrom_buffer, closes #3712885

[dataimport] Prevent ucsvreader from skipping the first line when ignore_errors is True (closes #3705791)

[dataimport] Avoid double unicode decoding in ucsvreader (closes #3705752)

[doc] Document the user_data dictionnary content

[debian] break old cubicweb-vcsfile We removed call_service's async argument, which it used.

[services] catch missing group early in register_user Better an assertion than a rql syntax error for such a programming error.

[services] rename register_user kwargs to cwuserkwargs They're attributes/relations for the created CWUser, this makes it clearer.

[services] don't hardcode 'users' group for register_user Let the caller choose which group the user should be in. Related to #3020639 Caveat: this is a possible security hole if untrusted values are allowed.

[sobjects/test] check that register_user properly sets user name and email address Related to #3020639

[server] Refactor Repository.register_user into a CubicWeb service (closes #3020639) [jcr: move commit to the caller; add item in release notes; fix NameErrors]

[migration] set a cnxset before process_script() Not pretty, but I don't have a better idea right now and this at least ensures migration scripts get run in the expected environment and can access sql stuff as before.