message: move getInitialLetter to Avatar so we can reuse it for editor pills
diff: @@ -176,7 +176,7 @@ module.exports = React.createClass({
  } = this.props;
  if (imageUrl === this.state.defaultImageUrl) {
  - const initialLetter = this._getInitialLetter(name);
  + const initialLetter = AvatarLogic.getInitialLetter(name);
  const textNode = (
  <EmojiText className="mx_BaseAvatar_initial" aria-hidden="true"
  style={{ fontSize: (width * 0.65) + "px",
  