Support extra html attributes on css replacement

Allow extra html attributes on css include replacement, the same way as it currently works for javascript includes.


Currently this block:
```html
<!-- build:css(build/static/) /static/css/print.css media="print" -->
      <link rel="stylesheet" href="/css/print.css" type="text/css" media="print" />
<!-- endbuild -->
```

will produce: 
```
    <link rel="stylesheet" href="/static/css/print-c10c1037.css">
```

After the patch the output will be:
```
    <link rel="stylesheet" href="/static/css/print-c10c1037.css" media="print">
```