remove some obsolte files
[confetti] / courses /
drwxr-xr-x   ..
-rwxr-xr-x 1128 edit_course.sh
-rwxr-xr-x 839 export_ical.sh
-rwxr-xr-x 4678 export_pdf.sh
-rwxr-xr-x 721 index.cgi
-rwxr-xr-x 1696 l10n.sh
-rwxr-xr-x 3956 list.sh
-rwxr-xr-x 1360 new_course.sh
-rwxr-xr-x 5549 update_course.sh
-rwxr-xr-x 10274 widgets.sh