[dataimport] Fix use of _create_copyfrom_buffer() (related to #3845572) This is used indirectly by SQLGenObjectStore when running on a PostgreSQL database. Regression introduced by commit 70056633085c.

[c-c configure] make it possible to specify the section for sources configuration (closes #3477678)

[server] fix 'cnx' variable confusion in DBG_SQL exception case The rollback handling expects 'cnx' to be the cubicweb Connection, but the DBG_SQL block was replacing it with an sql connection, leading to lulz down the line. Also remove obsolete getattr (the sqlite wrapping is now done at the cnxset level, so cnx.cnxset.cnx should be the right thing already).

Provide sufficient context to check 'delete' permission in AjaxEditRelationCtxComponent Call rdef.check only when both fromeid and toeid are available. Though only call it once (for the first encountered related entity). Factorize a bit to keep handling of CSS/JS addition the same. Closes #3670209.

merge 3.19.6 into 3.20 branch

Added tag cubicweb-version-3.19.6, cubicweb-debian-version-3.19.6-1, cubicweb-centos-version-3.19.6-1 for changeset 934341b848a6

[test] missing unittest.main() call in unittest_http_headers.py

[test] make unittest_webconfig independant of CWD if apphome is unset in ApptestConfiguration constructor, this later looks for a 'data' directory in CWD, making this test runnable only from web/test (and pytest do chdir before executing tests, so we did not noticed this problem).

[webctl] do not ask questions if verbosity is at 0 Closes #4641960.

[web] Slight tweak on jQueryUI's colors on links (related to #4564046) Follow up to commit 16f550b48d57 which was somewhat brutal. This change only overrides jQueryUI's CSS rules inside tab panes and leaves actual tab buttons alone.