Add wsdd support

[Schimmelreiter]

Greetings!

Maybe you could add wsdd (WS-Discovery) support too?

There is a wsdd+llmnr-Responder here: https://github.com/tobiaswaldvogel/openwrt-addpack/tree/master/wsdd/src but it doesn't support IPv6.

It would be great if we could have all three at the same time: wsdd AND llmnr AND IPv6 support.