prepare 3.16.1

[views/primary] some inner sections should use the `limit` by default to avoid a denial of service (closes #2719110) Today, it is possible to call .related and get a huge unlimited database-dos-inducing resultset that will be nevertheless limited a bit further in pure python in the `autolimited` view. While we cannot completely avoid potential denial of services such as these we mitigate the problem with the default ui settings: if the inner vid is `autolimited`, then the relation result sets is computed using the user-defined limit. This change respects the semantics of the `autolimited` view and shouldn't break anything.

[entity] ensure the .related(entities=False) parameter is honored all the way down (closes #2755994) As of today, such a call will always fill the relation cache by calling .entities() on every single related rset entry. As a consequence, the `limit` parameter handling also had to be fixed. It was bogus in the following ways: * not used in the related_rql, hence potentially huge database requests, but also actually * foolishly used in the .entities()-calling cache routine we now bypass (this changeset ticket's main topic) Now: * we set a limit on the rql expression, and * forbid caching if given a non-None limit (as we don't want to make the cache handling code more complicated than it is already) With this, entity.unrelated gets a better limit implementation (so the code in related/unrelated is nice and symmetric) Risk: * _cw_relation_cache disappears completely, which is good, but this is Python, so you never know ...

[test/web] fix invisibly bogus test (prepares #2755994) The test was wrong but that was cancelled out by a cache effect and fuzzy naming. Wiping the entity caches restores sanity: the choices list are the same before and after the SET. Also field.choices uses entity.unrelated but always returns related + unrelated elements. Hence `choice` replaces `unrelated` where it makes sense. AssertIn is used in place of AssertTrue.

[cwconfig] Fix exception handling when building the cube dependency graph UnorderableGraph exceptions do not have a 'cycles' property. A simple cast to str does the job.

[merge] backport stable fixes

[test/sobject] fix test regression Was complaining: - * updated comment #EID (#EID) ? ^^^^ + * updated comment #EID (duh?) ? ^^^^ in sobjects/test/unittest_supervising.

[web/request] Prune extraneous 'pageid' from generated ajax URL parameters (closes #2758130) If 'pageid' is given through extraparams, it is sent twice to the browser. On the JS side, the final URL loadxhtml() will end up using will have 'pageid' set twice which CubicWeb will readily accept as a list. Pruning this parameter makes sure it is exactly once.

[web/component] Use global variable to point to ajax controller (part of #2758254)

[web] Use the new '/ajax' URL path to access the AjaxController (closes #2758254) 5a81fa526b30 took care of all the JS code, this patch cleans up the remaining python bits.

[devtools/httptest] fix syntax error introduced by ce5ae7b80d2c

[component] Fix URL generation for navigation component (closes #2464832)