patch applied (cabal): Add new Command abstraction for handling command line args

Fri Nov 16 06:12:25 PST 2007 Duncan Coutts * Add new Command abstraction for handling command line args Add instances of it for all existing Cabal commands. This should makes command line handling more regular and hopefully make it easier to override or make derived commands in cabal-install. So far we're only adding code, not modifying existing stuff except renaming some existing internal functions so they do not clash with the new code. A ./Distribution/Simple/Command.hs M ./Distribution/Simple/Setup.hs -13 +542