Philippe Pepiot <philippe.pepiot@logilab.fr> [Thu, 28 Mar 2019 10:33:54 +0100] rev 12549
[cwconfig] drop importing legacy cubes
This finally drop support for legacy cubes.
In cwconfig, don't load modules in the "cubes" namespace.
In cube_pkginfo() handle CW_MIGRATION_MAP which wasn't working with new style cube.
Drop all method specific to legacy cubes importer: cubes_search_path(), extrapath(), cls_adjust_sys_path()
Drop environment variables related to legacy cubes: CW_CUBES_PATH and CW_CUBES_DIR