support dor uploading in a parent album

[gaubry]

As far as I understand, there is no possibility to upload the folder to a specific sub album, like what should be the --parent_album_id option in the piwigo_import_tree.pl script (https://piwigo.org/doc/doku.php?id=user_documentation:tools:piwigo_import_tree).

[blackisle51]

+1 From me, this would be a great addition to a very useful tool :)