Add an option to prevent minify from html embedded css

Even if this behavior is a good idea for production files, it's pretty annoying during the devel one because when i (only) want to format my html tags, my css will become unreadable at the same time :/ :

from :

```

(...)

a.input {
float: right;
}

```

to :

```

(...)

a.input { float: right; }

```

ps : ty about your great work :).