[source storage] on deletion, entity has no edited_attributes

[cleanup] rename dbms_helper to dbhelper for consistency

[entity] we also have to override dict.pop to properly maintain edited_attributes consistency

[bfss test] some minor refactoring. Test deletion + creation/update/deletion rollback

don't put hooks deleting orphan composites into the 'integrity' category, we usually want it when integrity is deactivated

[facet] allow to specify a target type on relation facets for case such as Keyword/CodeKeyword where we only targets Keyword

don't rewrite config's url during migration

le patch rql26 a été importé

backport stable

[D] book: update backup procedures in additional tips

[cleanup] remove accidentaly commited print

[test] don't try to reset session manager during test, this leads to weird failures when running multiple tests

don't update dontcheck until everything went fine: see usage in after_update_entity, where if we got an Unauthorized at hook time, we will retry and commit time.

[test] having two eid relations is now forbiden by rql

[web test] a basic test, to be completed