delay during load

[pszeszko]

What about add configurable delay during image load. This will allow to load elements in order.
Simple example:

 else if (elem.src !== (src = elem.getAttribute('data-echo'))) {
           // elem.src = src;
          var setSrc = function(elem1, src1) {
              elem1.src = src1;
          };
          setSrc.delay(i/length, elem, src);
        }