The hash of the changeset was not the correct one

This allow the removal of _is_namespace which is based on pkg_resources that is
deprecated.

modutils code is very old and hard to evolved and maintained and it also
depends of both imp and pkg_resources which are deprecated old modules that
will be removed in the future from the core python libraby.

So starting by removing everything that is not needed is a first step to get
ride of those problems.

This cleanup is based on this analysis:

List of used symbols
--------------------
* LazyObject
* load_module_from_name
* clean_sys_modules
* cleanup_sys_modules
* load_module_from_file
* modpath_from_file

Internal symbols needed by the used symbols
-------------------------------------------
LazyObject
    load_module_from_name
        load_module_from_modpath
            find_module[imp]
            load_module[imp]
            _is_namespace <- pkg_resources

load_module_from_file
    modpath_from_file (deprecated)
        _canonicalize_path
        _check_init

    load_module_from_modpath
        find_module[imp]
        load_module[imp]
        _is_namespace <- pkg_resources

feat!: remove deprecated code logilab.common.testlib.with_tempdir/within_tempdir/TestCase.assertItemsEqual/DocTest

feat!: remove deprecated argument optdict['inputlevel'] to logilab.common.configuration.OptionsManagerMixIn.add_optik_option