What do you think about "upgrading" `Compose.append()` to accept the `draft.content` array?

Something like this:

```js
append: function(item) {
  var fragment, items, length;

  if (Array.isArray(item)) {
    items = item;
    length = items.length;
    for (item of items) {
      if (item.blob) {
        this.append(
          new Attachment(
            item.blob, {
            name: item.name,
            isDraft: true
          })
        );
      } else {
        this.append(item);
      }
    }

    return this;
  }

  fragment = insert(item);

  if (document.activeElement === dom.message) {
    // insert element at caret position
    var range = window.getSelection().getRangeAt(0);
    var firstNodes = fragment.firstChild;
    range.deleteContents();
    range.insertNode(fragment);
    this.scrollToTarget(range);
    dom.message.focus();
    range.setStartAfter(firstNodes);
  } else {
    // insert element at the end of the Compose area
    dom.message.insertBefore(fragment, dom.message.lastChild);
    this.scrollToTarget(dom.message.lastChild);
  }
  onContentChanged(item);
  return this;
},
```

Then there is no need for a new Compose method