winepulse: expose individual audio devices directly

At present, winepulse only exposes one input device and one output device. This patch adds support for individual audio devices, allowing (among other things) the same program to record from two devices at the same time. It also brings winepulse more in line with both winealsa et al. and Windows itself. The moveable "Pulseaudio" devices are still present, and should presumably be used by default.