code: function merge_config(top_config, base_config)
  {
      for (var option in top_config)
      {
          if (Array.isArray(top_config[option])) // handle array elements in the same order
          {
              if (!Array.isArray(base_config[option]))
                  base_config[option] = top_config[option];
              else
              {
                  for(var i=0;i<top_config[option].length;i++)
                  {
                      if (base_config[option].length <= i)
                          base_config[option].push(top_config[option][i]);
                      else
                          merge_config(top_config[option][i],base_config[option][i]);
                  }
              } 
          }
          else if (typeof top_config[option] === "Object") // recurseively handle complex configurations
          {
              if (base_config[option] === undefined)
                  base_config[option] = top_config[option];
              else
                  merge_config(top_config[option], base_config[option]);
          }
          else
              base_config[option] = top_config[option];
      }
  
  }
docs: copy app_config configurations over package configurations