Changes made by me: - Move all error handling code into mdns_resp_announce() so it can be safely used by external code - Remove mdns_resp_netif_settings_changed() because it is the same as mdns_resp_announce() after my changes - Declare #define for a "thread-safe" version of mdns_resp_announce in mdns.h instead of netifapi.h - I don't want to intermix netif API with APPs