Returns the library for a given classname, supports private files
@param className
@returns {*}
function(className) {
      var t = this;
      var info = this.__classFiles[className];
      if (info) {
        return info.library; 
      }
      
      for (var j = 0; j < t.__libraries.length; j++) {
        var library = t.__libraries[j];
        info = library.getSymbolType(className);
        if (info && (info.symbolType == "class" || info.symbolType == "member")) {
          return library;
        }
      }
      
      return null;
    }