[test] Replace logilab-common's with_tempdir by tempfile.TemporaryDirectory
logilab-common's with_tempdir decorator, which is considered harmful (see
https://www.logilab.org/ticket/8267966).
Rely on backports.tempfile to provide TemporaryDirectory on Python 2.
Re-export it in testlib module for convenience.
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/html/index.html
Files: /usr/share/doc/cubicweb-documentation/html/*