Group in different files instead of one file

[stol]

Hi,

thank you for this interessting tool :)

Could you make it possible group queries in different files instead of one file ?

Ex :

$ group-css-media-queries --split name.css
$ #outputs name-global.css, name-min-481-max-768.css, name-min-450-max-770.css

Thank you !

[ivankravchenko]

Good and essential feature. Yandex is using this kind of separation.
I'll make this when it will be needed on our production or when I found free time for this.
Of course, I accept pull requests :)