add note about emulator performance

    <li>Fixed the missing JAR file error that prevented <code>draw9patch</code> from running.</li>

    <li>Fixed the Windows launch scripts <code>hierarchyviewer</code> and <code>ddms</code> to support

    the new location of <code>adb</code>.</li>

    <li>Known issues with emulator performance: Because the Android emulator must simulate the ARM

instruction set architecture on your computer, emulator performance is  slow. We're working hard to

resolve the performance issues and it will improve in future releases.</li>

  </ul>

</dd>

</dl>