allow FU to add to subproperties of a FUB option
allow FU to add to subproperties of a FUB option

SimonWaldherr/uploader,SimonWaldherr/uploader,FineUploader/fine-uploader,SimonWaldherr/uploader,FineUploader/fine-uploader,SimonWaldherr/uploader,SimonWaldherr/uploader,SimonWaldherr/uploader,FineUploader/fine-uploader,SimonWaldherr/uploader