[views] visual refactorings (closes #3803685) - pageContent: - remove the shadow - add a light border - slightly round the corners - left column: - ensure width make it aligned with the logo (header) - ensure the top border of the first box is aligned with the pageContent div - do not use serif font for box headers

[web] everything old is new again Kill the "new" cubicweb.css, and move cubicweb.old.css back in its place. Closes #4763360.

[pkg] bump version to 3.20.0

[views] use icons for user menu and login (header) (closes #3803684) - use icons from the embedded pictograms font for: - authenticated user menu (userActionsBox) - login (CookieLoginComponent) - do not display "anonymous" when not logged in

[utils] provide a function to return an admin connection from an appid Closes #4723580.

[debian] Install wsgi directory in cubicweb-web package Closes #4752375.

[test] fixes to make tests pass with recent lxml lxml (on jessie at least, ie. 3.4.0) does not remove endlines anymore.

[server] Remove useless 'is None' checks 'pb' is never none since 3386fd89c914 when support for the 'APYCOT_ROOT' env var was removed.

[security] check attributes: dispatch on the "add" action if entity was just created cw_set on a just-created entity (i.e. created in the same transaction) should behave the same as setting the attribute directly on creation: check the 'add' permissions, not 'update'. Closes #4740310.

[doc] Add BigInt to the list of built-in types

[devtools] call turn_repo_off in tearDown (closes #4673491) lets it catch leaked sessions even when running a single test

[book] typos / clarifications in create-instance section Clarify that cubicweb-ctl upgrade needs to be run whenever cubicweb or a cube is upgraded. Related to #2632425.