Add the file types we say we support.  PHP and PY were mentioned, but not allowed.
(cherry picked from commit 8ec4ba95780716c30eee1a1e334bca66e20e561d)
Fix events config screen to allow selecting more than .sh

The File Manager and upload code handle putting files in the right
directories when they are uploaded, so there isn't a big reason to
filter the results in the events UI code as well, so just filter
out . and .. for now.