patch applied (cabal): Add --list-options flag, should be useful for shell command line completion

[Duncan Coutts]

Mon Dec 17 05:20:48 PST 2007  Duncan Coutts <duncan at haskell.org>
  * Add --list-options flag, should be useful for shell command line completion
  It applies at the top level in which case it lists the global flags and
  the sub-commands. It applies for each sub-command in which case it lists
  the sub-command's available flags.

    M ./Distribution/Simple.hs +3
    M ./Distribution/Simple/Command.hs -25 +50