isNode = function(node, name) {
    if (node && node.nodeName) {
      if (typeof name === 'string') {
        name = [name];
      }
      for (var n = name.length; n--;) {
        if (node.nodeName === name[n]) {
          return true;
        }
      }
    }
    return false;
  }
Inserts an <img>
If selection is already an image link, it removes it

@example
   // either ...
   wysihtml5.commands.insertImage.exec(composer, "insertImage", "http://www.google.de/logo.jpg");
   // ... or ...
   wysihtml5.commands.insertImage.exec(composer, "insertImage", { src: "http://www.google.de/logo.jpg", title: "foo" });