fix for @-moz-document url-prefix issue

Fix for Issue https://github.com/livingston/css3-mediaqueries-js/issues/8

Usage of @-moz-document url-prefix within @media queries causes IE8 to crash when processing

Updated the regex for sanitizing @-moz-document url-prefix blocks
```javascript
REDUNDANT_COMPONENTS: /(?:\/\*([^*\\\\]|\*(?!\/))+\*\/|@import[^;]+;|@-moz-document\s*url-prefix\(\)\s*{(([^{}])+{([^{}])+}([^{}])+)+})/g,
```

This regex can probably be cleaned up a little, but this should match and filter out any usage similar to the following:
```css
@media only screen and (min-width: 1025px) {
    #hero{
        margin-top: 180px;
        margin-bottom: 110px;
    }
    
    @-moz-document url-prefix() {
        #hero .content-inner{
            width: 800px;
        }
        #other{
            width: 600px;
        }
    }
    
    #hero .paragraph{
        width:375px;
    }
}
```

The regex basically will match a @-moz-document url-prefix() selector with multiple nested CSS rules