[predicates] Fix reference to has_related_entities in partial_has_related_entities docstring

Fix possible double import of cubes modules When cubes using the new layout are imported with 'cubicweb_<cube>' and with 'cubes.<cube>', the same module is imported twice. Handle this by adding 'cubes.<cube>' to sys.modules when importing from 'cubicweb_<cube>'. Move load_module() to a sub class _CubesLoader to share informations computed in find_modules(). Don't handle subpackages in _CubesImporter and rely on normal import machinery instead. Add a test and use unittest from cubicweb.devtools.testlib which resolve to unittest2 on PY2 with assertLogs() method.

Make load_module() return existing module if present in sys.modules Otherwise the reload() builtin will not work correctly: https://www.python.org/dev/peps/pep-0302/#specification-part-1-the-importer-protocol

[server] Ignore computed relations in "relations" integrity checker

[server] Use global registry variable of integrity checker functions Instead of querying globals() in checkintegrity.check(), we maintain a _CHECKERS dict mapping checker name to function in checkintegrity module. This is later used to build the list of available checkers in 'db-check' command help.

[doc] Add 3.25 release notes [ci skip]

[repository] possibility to disable connections pooling Add a new configuration option 'connections-pooler-enabled' (default yes). If set to no, disable connection pooling and open new connections to the database on demand. This allow to use CubicWeb with other poolers (such as pgbouncer).

[js] Fix loading image URL

[migration] Move pyramid-related migration after "entities" table modifications Otherwise, we getting into `add_entity_type('CWSession')` we try to insert a CWEType without any 'asource' column (per 3.24's schema) whereas the backend still wants it. Closes #17054035.

Merge 3.24.5 into default branch

[entities] Introduce an IDublinCore adapter Move all dc_ methods from AnyEntity to the new IDublinCore adapter and proxy them through a __getattr__ method on AnyEntity. Current test suite should be enough. Closes #3119992.

[skeleton] Add an entry point and configuration for running a Pyramid application We add a `pyramid_main` function in __init__.py that instantiate the WSGI application using "cubicweb.pyramid"; this is defined as an entry point (in setup.py) so that pserve_ can find it. Alongside comes a development.ini file which includes basic settings so that running a Pyramid+CubicWeb application works (only the "instance=<appid>" may be passed as a command-line argument). Logging is also configured there, but only includes the cube at stake and cubicweb (others could be added if needed). .. _perse: \ http://docs.pylonsproject.org/projects/pyramid/en/1.8-branch/pscripts/pserve.html

[cwconfig] Issue a warning when a "core" ctl plugin failed to load This is often because of a missing dependency, the warning would indicate this hopefully.

[dataimport] Fix "existing_relations" parameter name in ExtEntitiesImporter

[ical] Create ICal events or todos depending on component type returned by adapter