Copy blessed files as fallback command during webpack building

[Verten]

When the blessed starting, it will looking xterm file to start.

Tput.prototype.setup = function() {
  this.error = null;
  try {
    if (this.termcap) {
      try {
        this.injectTermcap();
      } catch (e) {
        if (this.debug) throw e;
        this.error = new Error('Termcap parse error.');
        this._useInternalCap(this.terminal);
      }
    } else {
      try {
        this.injectTerminfo();
      } catch (e) {
        if (this.debug) throw e;
        this.error = new Error('Terminfo parse error.');
        this._useInternalInfo(this.terminal);
      }
    }
  } catch (e) {
    // If there was an error, fallback
    // to an internally stored terminfo/cap.
    if (this.debug) throw e;
    this.error = new Error('Terminfo not found.');
    this._useXtermInfo();
  }
};

The final try is call method this._useXtermInfo();

Tput.prototype._useXtermInfo = function() {
  return this.injectTerminfo(__dirname + '/../usr/xterm');
};

If we only build bundle.js, and the system ENV hasn't the xterm, the program will start failed. So add these missing files when build executable file.