remove 3.8 bw compat
- cwconfig: old keys such as depends_cubes and non-dict dependencies
- cwctl: fall back to docstring if no short descr, forget
'short_descr'
- dbapi: session_data, get_session_data, set_session_data,
del_session_data
- dbapi & testlib, session: eid_key is gone
- migractions: cachekey is gone
- doc/datamodel/definition, schemaserial: BoundConstraint ->
BoundaryConstraint
- formwidgets: separator
- primary view: render_entity_metadata
Related to #2782004.
What's new in CubicWeb 3.18?
============================
New functionalities
--------------------
* add a security debugging tool
(see `#2920304 <http://www.cubicweb.org/2920304>`_)
API changes
-----------
* not really an API change, but the entity permission checks are now
systematically deferred to an operation, instead of a) trying in a
hook and b) if it failed, retrying later in an operation
Deprecation
---------------------
Deprecated Code Drops
----------------------
* ``ldapuser`` have been dropped; use ``ldapfeed`` now
(see `#2936496 <http://www.cubicweb.org/2936496>`_)
* all 3.8 backward compat is gone