Suggestion: Add "delay" for tracks sent via DLNA server

[simoncn]

This initial segment of silence should be sent only for the first track of the playing queue. If it is sent for every track, it would cause gaps between the tracks. Only the renderer (not the server) can do this correctly because the server cannot know which track is "first" in the renderer's playing queue.

I have experienced this myself with my dCS Rossini. My renderer (Melco N1 USB-DAC) has a "Precision Start" setting to control this initial gap and I have found that a setting of 0.75 seconds works well for me.