MSACM: implement acmDriverPriority with driver priority/enabled saving

[Alex Villací­s Lasso]

Alex Villací­s Lasso wrote:

> This patch implements acmDriverPriority(), including saving the 
> priority order and the enabled/disabled status of each global driver 
> to  HKCU\\Software\\Microsoft\\Multimedia\\Audio Compression 
> Manager\\Priority v4.00 . Also included the foundation for broadcast 
> notifications on driver priority reorder, including a counter instead 
> of a BOOL flag for deferred notifications (as requested by Eric Pouech).
>
> Changelog:
> * Implementation of acmDriverPriority() with registry saving
> * Foundation for notification broadcasts with support for deferred 
> notification.
>
> Alex Villacís Lasso
>
Any comments on this patch?

Alex Villacís Lasso