[dxdiagn] DirectXFiles + bug fixes

[Christian Costa]

>
>
>Todo:
> - find a way to provide wanted informations on containers (logical drivers, 
>sound drivers, display drivers, ...)
> - fill DirectShowFilters (Christian have you an idea how to do that ?)
>  
>
Well, I don't know which filters should be enumerated here but you can use
devenum (see EnumMatchingFilters of IFilterMapper2 interface).

Christian