[application] call req.set_session in application.main_handle_request
The Session handling chain is no more responsible for calling req.set_session.
It just returns a valid session and lets the caller link it to the Request.
This opens the way to explicitly creating and closing a connection/transaction
in ``application.main_handle_request``.
Related to #2503918
include README
include COPYING
include COPYING.LESSER
include pylintrc
include bin/cubicweb-*
include man/cubicweb-ctl.1
recursive-include doc README makefile *.conf *.js *.css *.py *.rst *.txt *.html *.png *.svg *.zargo *.dia
recursive-include misc *.py *.png *.display
include web/views/*.pt
recursive-include web/data external_resources *.js *.css *.py *.png *.gif *.ico *.ttf
recursive-include web/wdoc *.rst *.png *.xml ChangeLog*
recursive-include devtools/data *.js *.css *.sh
recursive-include i18n *.pot *.po
recursive-include schemas *.py *.sql
recursive-include test/data bootstrap_cubes *.py *.sql
recursive-include entities/test/data bootstrap_cubes *.py
recursive-include sobjects/test/data bootstrap_cubes *.py
recursive-include hooks/test/data bootstrap_cubes *.py
recursive-include server/test/data bootstrap_cubes *.py source* *.conf.in *.ldif
recursive-include devtools/test/data bootstrap_cubes *.py *.txt *.js
recursive-include web/test/data bootstrap_cubes pouet.css *.py
recursive-include web/test/jstests *.js *.html *.css *.json
recursive-include web/test/windmill *.py
recursive-include skeleton *.py *.css *.js *.po compat *.in *.tmpl
prune doc/book/en/.static
prune doc/book/fr/.static
prune doc/html/_sources/
prune misc/cwfs
prune goa