Support media query NOT operator

[wc-matteo]

I find this plugin incredibly useful! Great job! ;)

Recently, I adopted the media query not operator to emulate a less than check:

@media not all and (min-width: 80em) {}
@media (min-width: 80em) {}

• not must be followed by all and to work.

But it seems unmq currently doesn't support this (I guess it interprets the first mq the same way it does the second). Would it be much work to implement it?

[jonathantneal]

For better and worse, the logic in this plugin is very simple and relies on an internal test from https://github.com/ericf/css-mediaquery (see line 3 and line 34) so unfortunately, this might be an issue with css-mediaquery.