message: first impl of inline formatting
diff: @@ -455,22 +455,26 @@ export default class BasicMessageEditor extends React.Component {
  });
  }
  - _formatBold = () => {
  + _wrapSelection(prefix, suffix = prefix) {
  const {partCreator} = this.props.model;
  this._replaceSelection(range => {
  const parts = range.parts;
  - parts.splice(0, 0, partCreator.plain("**"));
  - parts.push(partCreator.plain("**"));
  + parts.splice(0, 0, partCreator.plain(prefix));
  + parts.push(partCreator.plain(suffix));
  return parts;
  });
  }
  - _formatItalic = () => {
  + _formatBold = () => {
  + this._wrapSelection("**");
  + }
  + _formatItalic = () => {
  + this._wrapSelection("*");
  }
  _formatStrikethrough = () => {
  -
  + this._wrapSelection("<del>", "</del>");
  }
  _formatQuote = () => {
  