Make file/folder permissions configurable.

[JimBacon]

The warehouse application creates files and folders as part of its normal behaviour. Currently the permissions assigned are hard-coded.

E.g. in modules/rest_api/controllers/services/rest.php there is this snippet

      $dest = DOCROOT . "upload-queue/$subdir";
      if (!is_dir($dest)) {
        mkdir($dest, 0755, TRUE);
      }

The permissions should be configurable to suit different server environments.