[WIN32] workaround: get the default audio interface for DirectSound to have audio on a fresh installation.

Thats not a fine way of doing it but it works at least. On my setup (connected speakers) AE always choose spdif as default interface on a fresh installation. As a result I don't have any sound.
The problem is that AE just chooses the first device from the devicelist and treads it as default interface (passthrough=false).
I assume a better way would be to let the sink return the default interface or add a flag to CAEDeviceInfo. But what do I know...
This is for >=Vista only.