@Ankostis, I was looking at your bug fix for the "rename-files" branch and noticed what might be a tiny issue. On line 69 of /res/ext.SimpleBatchUpload.js you changed:
var dst_filename = '';
to
var dst_filename = src_filename
I swear I'm not trying to be glib here, but are you missing a semicolon after "src_filename"?
https://github.com/ankostis/SimpleBatchUpload/compare/master...ankostis:rename-files