_addGhostPos = function(e, ghost) {
  if (!ghost.x) {
    ghost.x = parseInt(e.pageX - ghost.draggedItem.offset().left);
  }
  if (!ghost.y) {
    ghost.y = parseInt(e.pageY - ghost.draggedItem.offset().top);
  }
  return ghost;
}
_addGhostPos clones the dragged item and adds it as a Ghost item
@param [object] event - the event fired when dragstart is triggered
@param [object] ghost - .item = node, draggedItem = jQuery collection