message: clarify why we need this
diff: @@ -648,6 +648,10 @@ module.exports = React.createClass({
  const isAtBottom = scrollPanel.isAtBottom();
  const whoIsTyping = this.refs.whoIsTyping;
  const isTypingVisible = whoIsTyping && whoIsTyping.isVisible();
  + // when messages get added to the timeline,
  + // but somebody else is still typing,
  + // update the min-height, so once the last
  + // person stops typing, no jumping occurs
  if (isAtBottom && isTypingVisible) {
  scrollPanel.blockShrinking();
  }
  