Automatically call stop() on ssb.close()

[christianbundy]

I'm running ssb.close() to close my peer, but when this plugin is loaded the process stays open. My current workaround is ssb.lan.stop(); ssb.close() but I think it might be nice to hook ssb.close() similar to other plugins (e.g. SSB-Serve-Blobs (ssbc/ssb-serve-blobs@ff13928)).

[staltz]

Agreed!