Handle 'Offensive For Everyone'

[adenosie]

Currently, when an article with 'Offensive For Everyone' flag (aka visibility flag) is requested, the parser fails. We should work around this, because no one wanna crash every time they request wrong article only because they were naive and .unwrap()'d the result.

The solution for this involves a cookie to be set, but we haven't yet done any feature involving cookies. So this would take a lot of work. But login session would need a cookie too, so this should be done someday.