code: function(url, fromFilename, toFilename) {
  
  		if (!SKIP_URLS.test(url)) {
  
  			var fromDirname = path.dirname(fromFilename),
  				toDirname = path.dirname(toFilename),
  				fromPath = path.resolve(fromDirname, url),
  				toPath = path.resolve(toDirname);
  
  			return path.relative(toPath, fromPath).replace(/\\/g, "/");
  		} else {
  			return url;
  		}
  	}
docs: Translates a given relative URL with consideration that the reference is
  relative to a specific CSS file, and that CSS file location is changing.
  @param {string} url The URL to translate.
  @param {string} fromFilename The original filename for the CSS.
  @param {string} toFilename The new filename for the CSS.
  @returns {string} The CSS code with the URLs translated.