message: support extra cmd
diff: @@ -100,7 +100,7 @@ export namespace Launcher {
  cmd.push('-Dfml.ignorePatchDiscrepancies=true');
  //add extra jvm args
  - // if (options.extraJVMArgs) cmd.push(options.extraJVMArgs);
  + if (options.extraJVMArgs) cmd = cmd.concat(options.extraJVMArgs);
  cmd.push('-Djava.library.path=' + mc.getNativesRoot(version.root));
  @@ -137,8 +137,8 @@ export namespace Launcher {
  cmd.push(args);
  //extra mc args
  - // if (options.extraMCArgs)
  - // cmd.push(options.extraMCArgs);
  + if (options.extraMCArgs)
  + cmd = cmd.concat(options.extraMCArgs);
  if (options.server) {
  cmd.push(`--server ${options.server.ip}`)
  