Added a RebootFastbootBootloader() method

 /// <summary>
        /// Reboots the Bootloader from fastboot
        /// </summary>
        public void FastbootRebootBootloader()
        {
            if (this.State == DeviceState.FASTBOOT)
                new Thread(new ThreadStart(FastbootRebootBootloaderThread)).Start();
        }

        private void FastbootRebootBootloaderThread()
        {
            Fastboot.ExecuteFastbootCommandNoReturn(Fastboot.FormFastbootCommand(this, "reboot-bootloader"));
        }