[ FEATURE ] Command line argument "copy-buffer" input #655

Actually i expect it works like this:

1. Select something (in PHPStorm or textfile)
2. Copy / Cut
3. Press hotkey in your IDE (actually runs "csscomb -copy" as an hotkey alias for user command)
4. In background it creates a file, paste there a copied stuff, reformat it by rules, copies it back, removes file
5. Autopaste it back replacing selected stuff / or just paste if cut

Same like "format code" in Intellij works. If you select certain code - it works on this code only, dont touch the stuff written before.