DMD 0.167 release

[Walter Bright]

Derek Parnell wrote:
> By the way, I appreciate the new 'warning' message ...
> 
>  shadowing declaration <identifer> is deprecated
> 
> It has help me clean up some code that otherwise might have been a bit
> confusing to a code reviewer.

I like it too. It found several instances in my code of, while not 
outright bugs, definitely sloppy and confusing code.