title: Compass don't compile @charset rule
body: <p>I have <code>@charset "utf-8"</code> rule in my _base.scss partial and when I importing _base.scss in my master file @charset rule don't compile.
  I try <code>@viewport {width:device-width;}</code> and it compile fine but @charset don't. Any idea where is the problem?</p>
  
  <p>Yes it is the first rule in my _base.scss partial,I try other CSS @rules and they works fine but @charset don't want to compile in .css file.</p>