New `haibu-carapace` API

example.js

var fork = require('child_process').fork;

var c = fork('bin/carapace', ['examples/chroot-jail/server.js']);
c.on('message', function (data) {
  console.log('Received a message from carapace');
  console.dir(data);
  if (data.event == 'port') {
    console.log([
      'Server is listening on port ' + data.data.port,
      '(It wanted to listen on ' + data.data.desired + ')'
    ].join('\n'));
  }
});