[cwconfig] don't rely on _CubeImporter while loading cubes
_CubeImporter can load cube subpackages twice (there is a test for submodules
in cubicweb.test.unittest_cubes.test_no_double_import() but not with a
subpackage).
Since _CubeImporter is for backward compatibility and is supposed to be
deprecated as soon as possible, don't rely on it when loading cube schema or
appobjects and always load the real modname (eg. cubicweb_<cube> if exists else
cubes.<cube>).
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/python-cubicweb-documentation/html/index.html
Files: /usr/share/doc/python-cubicweb-documentation/html/*