title: ADT 23 doesn't like NDK11
body: <p>Win7-x64, Eclipse Luna SR2, Android tools v23.0.7. I've installed NDK r11. I'm trying to point Eclipse at <code>D:\android-ndk-r11</code> via the Preferences window, but it says: </p>
  
  <blockquote>
    <p>"Not a valid NDK directory".</p>
  </blockquote>