dinput: Implement DIPROP_KEYNAME property for keyboard device

[Vitaliy Margolen]

Sergey Khodych wrote:
>> No, there are 2 separate implementations - one ascii another unicode. During 
>> the object creation one would specify either ascii or unicode RIID.
> 
> Objects IDirectInputDevice8W and IDirectInputDevice8A has function
> GetProperty. This function get struct of type DIPROPSTRING as
> input/output parameter in our case . This struct has output field wsz of
> type WCHAR[ MAX_PATH ] and other input fields not depends of charset.
> So type of returned data will be WCHAR[ MAX_PATH ] in both case.
> So objects IDirectInputDevice8W and IDirectInputDevice8A has the same
> implementation of function GetProperty and this implementation is for
> Unicode in both case.
> 
> 
I'd like to see a test for this. So far I have not seen a case when ascii 
and unicode COM objects return the same exact unicode structure with unicode 
text. And we also seen number of cases when even SDK was wrong. Not even 
talking about MSDN.

Vitaliy