patch applied (cabal): Allow addKnownProgram to be used as an update, not just insert

[Duncan Coutts]

Wed Sep 17 15:58:56 PDT 2008  Duncan Coutts <duncan at haskell.org>
  * Allow addKnownProgram to be used as an update, not just insert
  ie preserves any existing user-supplied path and args

    M ./Distribution/Simple/Program.hs -1 +2

View patch online:
http://darcs.haskell.org/cabal/_darcs/patches/20080917225856-adfee-d2cb2f03032ffe239b51f574bd28295aaa2420e3.gz