New version of Dung Cabal package

This package version is now compatible with the translation package
CarneadesIntoDung.
See
http://hackage.haskell.org/package/CarneadesIntoDung/

This package has
furthermore been significantly extended and now includes:

* Preferred,
stable and semi-stable semantics along with all definitions from

Caminada's paper "An Algorithm for Computing Semi-Stable Semantics".

*
An Input module, allowing files in standard CEGARTIX/PrefSat format to
be parsed.

* An Output module, allowing AFs in this package to be
outputted in standard
  CEGARTIX/PrefSat format.

* A main executable,
allowing input files to be read, argumentation frameworks
  to be
outputted and evaluated.

Updated .cabal , LICENSE, etc. accordingly