IX Load _config.php's after static config manifest

This allows more sophisticated handling of config alterations
in _config.php. One example is additions to DataObject::$db
based on configuration which requires some processing.

See https://github.com/unclecheese/TranslatableDataObject/blob/master/TranslatableDataObject.php
Merge pull request #1317 from chillu/pulls/config.php-after-statics

FIX Load _config.php's after static config manifest