CRM-19303 - Drupal - Fix various path computations... * Update `[civicrm.files]`: First, try to use `sites... Otherwise, use `sites/default/files/civicrm`. ...parsed/validated the same way as `civicrm.config.php`. * Update `[civicrm.root]`: Compare `$civicrm_root... ...relative path. Then, combine `CIVICRM_UF_BASEURL` with