patch applied (packages/unix): Require Cabal version >= 1.6

[Ian Lynagh]

Wed Jan 21 17:13:31 PST 2009  Ian Lynagh <igloo at earth.li>
  * Require Cabal version >= 1.6

    M ./unix.cabal -1 +1

View patch online:
http://darcs.haskell.org/packages/unix/_darcs/patches/20090122011331-3fd76-6c42efaaccf4daa84bb6538b813b84ce59ff48b4.gz