Selector specificity not working for !important rules

When two selectors match the same element, and both have `!important`, then the selector specificity is ignored and the last rule wins:

``` Javascript
inlineCss('p a {color: red!important} a{color: black!important}

test', {url: '/'}).then(s=>console.log(s))
// '

test

'
inlineCss('a{color: black!important} p a {color: red!important}

test', {url: '/'}).then(s=>console.log(s))
// '

test

'
```

However for the browsers it’s different. [No matter which rule goes first, if both have !important in them, the more specific wins.](http://embed.plnkr.co/YChmIIhgzanpdgFUeTrK/)