OpenHome services

I consider OpenHome services **working** now

There are few things I think could be done:

 - cleanup shared_metadata module
 - moderate writes to playlist file
 - most important - sometimes, when changing tracks, there are huge lags before subscribed devices receive notifications. I have tracked this down to UpnpNotify() taking too long too execute, but have not found the reason and solution yet. Possibly this problem has something to do with the fact that control point periodically sends requests to Time service, and on track change many notifications are sent to different services, and action can somehow interfere with notifications