[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>).
.. _Part2:
----------------------
Repository development
----------------------
This part is about developing applications with the *CubicWeb*
framework. It is not concerned with the web system, which is a
separate layer and has its own whole chapter.
.. toctree::
:maxdepth: 2
:numbered:
cubes/index
vreg.rst
datamodel/index
entityclasses/index
devcore/index
repo/index
testing.rst
migration.rst
profiling.rst
fti.rst
dataimport