Fix main issues from #220

I used `encodeUtf8` or `Char.pack` instead of `ClassyPrelude.pack` where possible to resolve the compilation issues as outlined by @HounD in #220.

As this is IMO a critical bug making installation (and therefore usage) absolutely impossible, merging and subsequently releasing a bugfix would be highly appreciated.

There is (at least) one issue with UUIDs left that I'm currently trying to resolve.