perty named <code>$label</code> giving a
  human-readable display name for the configuration. Any other properties defined in the configuration are
  applied to the project when that configuration is active and override defaults in
  <code>nbproject/project.properties</code>.
 </li>
 <li>
  <code>nbproject/private/configs/<i>CONFIGNAME</i>.properties</code> is optional and can contain per-user
  settings for the indicated configuration. Any such properties override defaults in
  <code>nbproject/private/priv