message: Use writeFileSync instead of openSync+write
  Simpler and completely sync.
diff: @@ -100,16 +100,8 @@ const saveSEQ = (filename: string, fb: FramebufWithFont, fmt: FileFormatSeq) =>
  let bytes:number[] = []
  console.log(fmt) // placeholder for future use
  convertToSEQ(fb, bytes)
  - let length = bytes.length
  - let buff = new Buffer(length)
  - for(var i = 0; i < length; i++) {
  - buff.writeUInt8(bytes[i], i)
  - }
  - let fd = fs.openSync(filename, 'w')
  - fs.write(fd, buff, 0, buff.length, 0, function(err:any, written:any) {
  - console.log('err', err)
  - console.log('written', written)
  - })
  + let buf = new Buffer(bytes);
  + fs.writeFileSync(filename, buf, null);
  }
  catch(e) {
  alert(`Failed to save file '${filename}'!`);
  