[repo transaction] fix rollback behaviour as discussed on the mailing-list: instead of rollbacking automatically on Unauthorized/ValidationError, mark the transaction as uncommitable and disallow commiting

#1256570: remove __method, it is not used in any of the cubes from logilab and encourages bad design by using Redirect (eg ui specific) from entities.py

Add a fsimport context manage to localy enable fsimporting.

[test] improve tag for server/test/unittest_storage.py Use class level tag.

[repo threads] Add several safety when looking for a callable name. We lookup __name__ attribute, then func_name attribute. object repr is a last fallback

[facets] support for `no_relation` on RelationFacet e.g. to filter en entities *without* a given relation as well as with a particular relation. Proposed or not by default according to relation cardinality. Also, try to guess i18nable properly from the schema by default.

[R] use dbhelper.binary_value to process passwords and other Bytes fields (instead of dbapi_module.Binary or hardcoding buffer()). This requires (esp. in serverctl) version 1.3.1 of logilab.database. Dependencies updated.