Disruptive breaking change

[fiddlerwoaroof]

I use Yason extensively in my personal codebases and 7daea breaks all sorts of code that has been stable for years: before, yason would default to *standard-output* for encoding and now it defaults to the stream referenced by the unbound symbol *json-output*. This makes one of my primary use-cases (quickly testing things out at the repl) much more burdensome, because I have to either (setf yason::*json-output* *standard-output*) or add a bunch of boilerplate to make a json output stream.

The change itself makes sense because it makes :indent and friends less surprising but, IMO, it should be done in a non-breaking way.

[phmarek]

Hi Ed,

to be honest, I quite like that YASON requires some setup - this way a wrong call-path is easier to notice.

Would you be okay with just doing a (SETF ...) in your code base, or does this behaviour affect too many of your projects?