[tests/rqlannotation,querier] use the new connection api

[webtests/web] use the new connection api

[webtests/navigation] use the new connection api

[webtests/basetemplates] use the new connection api

[webtests/basecontrollers] use the new connection api

[testlib] deprecate .remote_call and provide new connection api friendly .remote_calling

[webtests/propertysheet] kill an "import *"

[webtests/breadcrumbs] break long lines

[webtests/views_editforms] use the new connection api

[webtests/urlrewrite] do not store a plain entity on the test, only an eid

[webtests/urlrewrite] use the new connection api

[webtests/urlpublisher] use the new connection api

[webtests/baseviews] use the new connection api

[devtools/testlib,fill] use the new connection api (for auto_populate) Note that this changes API of CubicWebTC's custom_populate and post_populate methods to take a connection instead of a cursor, which may affect some cubes.

[webtests/automatic views tests] use the new connection api

[devtools/repotest] simplify a very small helper

[tests/repotest] use the new connection api

[tests/querier] use the new connection api (part 3/3) Some adaptations to devtools/repotest: * dead code removal * remove session related code In the tests: * many tests actually don't check the querier but some generic rql property -- when such a test needs several statements to complete a commit, switch to session.new_cnx * provide an assertRQLEqual helper

[test/querier] use the new connection api (part 2/3) A couple of tests need a schema constraint to be dropped to pass with `.qexecute`.

[test/querier] use the new connection api (part 1/3) In devtools/repotest, we provide a simple `.qexecute` with autocommit, and we use it (where possible) in unittest_querier. Note that the .session object is a real session, not the magic property found in CubicWebTC test classes.

[dbapi] allow talking to a pre-3.19 remote repository Closes #4071285

[migration] don't add new elements to config._cubes in remove_cube We're expanding dependencies based on the current versions of the cubes, which may well not be the same as the ones known by the db (we're in the middle of an upgrade, after all). Listing them in config._cubes prevents us from calling add_cube() later to actually add them. Closes #4002156

[web test] repair test broken by 0872ac2a1db0 after the above cset, during test instance's url is set before the creation of core entities (ie created at database initialization), hence they have now a valid cwuri.

[dataimport] Drop reference to the 'source' column (closes #4067694). CW 3.19 drops the multi-source support. This column does not exist in 3.19.

[notification] drop on commit sending of message feature of NotificationView It duplicates feature already provided by cw.hooks.notification.notify_on_commit function. Simplify the API on the way.

[datafeed parser] enhance retrieve_url to support POSTing data and custom HTTP headers Closes #3682069

[datafeed parser] fix retrieve_url to always return urllib2.urlopen compatible output as one should expect to be able to call geturl/getcode/info on the returned object whatever the url he gave. Related to #3682069

[datafeed parser] factor out retrieve_url method from DataFeedXMLParser.parse Related to #3682069

[datafeed] Allow to override use_cwuri_as_url in configuration of a datafeed source This is necessary because in some case one will want to write parser which create entities not one-to-one related to entities from the distant source (for instance see the `vcrs` cube which create entities holding statistics for code review, while not importing review entities themselves). Ideally we should provide a way to the parser to indicate the source that cwuri should not be used, but that's a start... Closes #3670210

merge from 3.19 branch