code: static function run_list_extensions( $task=null, $args=array(), $cliopts=array() )
      {
          self::setConfigDir( $cliopts );
          $exts = self::getAvailableExtNames();
          switch( count( $exts ) )
          {
              case 0:
                  pake_echo ( 'Available extensions: -' );
                  break;
              case 1:
                  pake_echo ( 'Available extensions: ' . $exts[0] . ' (default)' );
                  break;
              default:
                  pake_echo ( 'Available extensions: ' . implode( ', ', $exts ) );
          }
      }
docs: Displays the list of extensions which can be built (which have a config file available in the pake subdir)