patch applied (cabal): Add a HACKING file

Sat Aug 22 08:16:36 PDT 2009 Duncan Coutts * Add a HACKING file Ignore-this: 222a83edbe3bf27574bfe51df7f109f0 Seems people do not know that the source guide exists. A ./HACKING View patch online: http://darcs.haskell.org/cabal/_darcs/patches/20090822151636-adfee-6c24647bd...