Add quality factors to content negotiation

[ThijsBroersen]

As a user I would also like quality factors within an Accept-header to be respected.
E.g.

Input
  .get("/test")
  .withHeaders("Accept" -> "text/plain;q=0.3,application/json;q=0.9")

Currently the quality factors are ignored.

[vkostyukov]

@ThijsBroersen Thanks for the ticket!

Not sure I follow the first part about being a multi-value. This should be supported (only qualities are ignored) and if not, it's a bug. Mind providing more details on this?

[ThijsBroersen]

@vkostyukov you are correct, it takes the first Content-Type that matches any value from the Accept-header. And when no match is found it returns the last Content-Type of a coproduct.
My tests were a bit off...