Allow "" as a valid value in a OptionsBox menu (reported by Guido Schimmels).
tree36dfbbaed425c796010b7f8485b9013d1acac9c4
-rw-r--r-- 4594 .DirIcon
-rw-r--r-- 966 AppInfo.xml
-rwxr-xr-x 873 AppRun
drwxr-xr-x - Help
-rwxr-xr-x 1563 MakeDist
drwxr-xr-x - Messages
drwxr-xr-x - python
drwxr-xr-x - tests