Handle cubes as packages in cwconfig Rely on importlib.import_module in several places in cwconfig.py, so this would not work with python 2.6. Method available_cubes will not list cubes installed as package for now. I'm not sure it's worth implementing this method (used in `cubicweb-ctl list cubes` command) for new cubes layout as the same result can basically be obtained with `pip freeze | grep cubicweb_`. In unittest_cwconfig.py, duplicate CubicWebConfigurationTC test case to test both the "cubes as packages" layout and the "legacy cubes" layout. The former having a custom sys.path set (pointing to datapath('libpython') where all cubes' packages live) and the latter having the previous config attribute setup. All test data cubes are moved to packages in libpython directory and symlinks are introduced in the cubes directory. Related to #13001466.

etc/init.d
etc/cubicweb.d
etc/bash_completion.d
usr/bin
usr/share/doc/cubicweb-ctl
var/log/cubicweb
var/lib/cubicweb/backup
var/lib/cubicweb/instances