Proposal #3337: expose Unicode and newline translation from System.IO

Ticket:

   http://hackage.haskell.org/trac/ghc/ticket/3337

For the proposed new additions, see:

  * http://www.haskell.org/~simonmar/base/System-IO.html#23
    System.IO (Unicode encoding/decoding)

  * http://www.haskell.org/~simonmar/base/System-IO.html#25
    System.IO (Newline conversion)

Discussion period: 2 weeks (14 July).