[ITP] mkvtoolnix and its dependencies

[David Stacey]

Recently, I had to process some video files [1] in the 'mkv' container 
format, and used mkvtoolnix for this purpose. I'm happy to maintain it 
in case it is useful to anyone else. There are four packages involved; 
I'll send separate ITP e-mails for each.

Dave.
[1] - Home movies, obviously ;-)