URI, JSON and formdata decoding no longer checks for control characters,
but FU::Validate now rejects control characters by default. This
decouples semantic validation from format parsing and gives better
control over when control characters are allowed.
And with this, I have a working rewrite of the manned.org backend into
FU. \o/
The $st->row methods are very useful even for queries that may not
return anything, so their old behavior was unhelpful. Interestingly
enough, the error-on-multiple-rows did catch an actual bug in
Manned.org, so I'm keeping that behavior.