Add fontName option to avoid random string
In my SCSS I'm using pluging as follows: 

```
...
[class^="icon-"], [class*=" icon-"] {
  font-family: iconfont-XXXXXX !important;
  ...
}

.icon-search:before {font-icon: url(img/icons/fontawesome-icons/search.svg);}
...
```

Every time after re-generating font files I need to replace that XXXXXX identifier. My recommendation is give user complete control using SCSS. For example, we could implement fontName option that would  set font-family CSS property to fixed specified string.

Am I missing something?
