`circe-split-line-length` not obeyed when line contains no whitespace

[TaylanUB]

When I post a very long string with no whitespace in it, Circe doesn't split it at all.

[wasamasa]

I suspect this is by design as it currently splits by whitespace. After all, it would look weird if your lengthy message got trunc

[jorgenschaefer]

Yeah, Circe should really split long lines hard at a given line length. It currently uses fill-region. I suspect we can't re-use that anymore. (We should pass NOSQUEEZE anyhow …)