PsyParallelPort for windows (and Mac)

[maartenuni]

PsyParallelPort is a abstract base class for PsyParallelPorts. On Linux there is a Non abstract implementation using parport.

The PsyParallelTrigger class uses a PsyParallelPort, in theory this class should work on windows if It would have an implementation for a parallel port.

So add a PsyWinParallelPort or use a better name for window parallel devices.