Unwrap an element from it's container

elem-unwrap.js

/**
 * Unwrap element 
 */
function unwrap(wrapper) {
  // place childNodes in document fragment
  var docFrag = document.createDocumentFragment();
  while (wrapper.firstChild) {
      var child = wrapper.removeChild(wrapper.firstChild);
      docFrag.appendChild(child);
  }

  // replace wrapper with document fragment
  wrapper.parentNode.replaceChild(docFrag, wrapper);
}