hotplug dsound: initial cut of properly working connectionIds. it works. it pulls...

hotplug dsound: initial cut of properly working connectionIds. it works. it pulls device information from each device every time, and then reuses the old connectionId if the GUID is the same. This has the advantage of always pulling updated channel count information. it has the disadvantage of re-polling every device, not just newly inserted/removed ones. the alternative is to reuse the existing device information by copying it over, which could be done.