Return errors for unrecognized query parameters

[lindholc]

According to the spec, a query with unrecognized parameters "should" (RFC 2119) return an error.

I wasn't able to figure out a way to do this when working on #9. Rather than spend more time on something that isn't strictly required, here's a ticket to consider figuring this out later.

[lindholc]

I've thought of an unpleasant way of doing this.

case GET -> Root / "hapi" / "info"
    :? IdMatcher(id)
    +& ParamMatcher(params)
    +& query => ???

query will be a Map[String, Seq[String]] mapping parameters to their values for the whole query. One could check the keys and return an error if any of the keys aren't the sanctioned ones.