asdf json library moved to libmir

[yannick]

Hi All,

Since i'll be leaving Tamedia (who sponsored development of Asdf) 
and it's not under active use anymore here we decided to donate 
it to libmir.

Asdf has a few nifty features that make it perfect for reading 
large amounts of json lines and transforming data. For an example 
use case see je, the json to csv transformer app ( 
https://github.com/tamediadigital/je )

I still think that it is by far the easiest to use and fastest 
production grade Json Library for D.
Maybe it should be renamed to reflect that, proposals welcome.

cheers,
y