code: function cleanCssUrlQuotes(url) {
          //Make sure we are not ending in whitespace.
          //Not very confident of the css regexps above that there will not be ending
          //whitespace.
          url = url.replace(/\s+$/, "");
  
          if (url.charAt(0) === "'" || url.charAt(0) === "\"") {
              url = url.substring(1, url.length - 1);
          }
  
          return url;
      }
docs: If an URL from a CSS url value contains start/end quotes, remove them.
  This is not done in the regexp, since my regexp fu is not that strong,
  and the CSS spec allows for ' and " in the URL if they are backslash escaped.
  @param {String} url