merge libs?

[yocontra]

Hey there -

Your lib looks cool, I want to use it instead of some stuff I wrote for react-responsive

Here is my stuff:

https://github.com/wearefractal/react-responsive/blob/master/src/toQuery.js

I think negation might be the only missing feature from json2mq - want to have a look at the code and see if there are any other gaps?