Don't filter out all events

@quantum5 @FatalEagle the socket server should probably require some form of authentication, but I guess public access to sub_* resources is not worth the effort. After all, all a malicious user could see is the number of test cases for a private problem.

Writing this I realize the `detail` page is uselessly hidden, since someone can just fetch the events themselves.

Maybe we should make the detail page publicly visible for all submissions, but keep the source hidden until the problem is solved. Thoughts?