* v0.8:
Don't leak writer and index goroutines on close
Clean up protocol locking and closing
Send initial index in batches
Always send initial index, even if empty (ref #344)
Simplify locking in protocol.Index
Protocol state machine on receiving side
Log client version on connect
Handle query parameters in UPnP control URL (fixes#211)
Avoid deadlock during initial scan (fixes#389)
Add temporary debug logging for #344 (revert later)
Tone down UPnP not found message (fixes#406)