/* Return an importer object for a sys.path/pkg.__path__ item 'p',
possibly by fetching it from the path_importer_cache dict. If it
- wasn't yet cached, traverse path_hooks until it a hook is found
+ wasn't yet cached, traverse path_hooks until a hook is found
that can handle the path item. Return None if no hook could;
this tells our caller it should fall back to the builtin
import mechanism. Cache the result in path_importer_cache.