Simplify the way we derive configure, install and upgrade commands

so we do not accidentally inherit the default flags for the underlying
configure command when we in fact want the empty flags. I am beginning
to suspect that having any defaults at all was a mistake.

cabal-install/Hackage/Setup.hs

@@ -62,11 +62,8 @@ globalCommand = Cabal.globalCommand {
       ++ "\nSee http://www.haskell.org/cabal/ for more information.\n"
   }
 
-cabalConfigureCommand :: CommandUI Cabal.ConfigFlags
-cabalConfigureCommand = Cabal.configureCommand defaultProgramConfiguration
-
 configureCommand :: CommandUI Cabal.ConfigFlags
-configureCommand = cabalConfigureCommand {
+configureCommand = (Cabal.configureCommand defaultProgramConfiguration) {
     commandDefaultFlags = mempty
   }
 
@@ -91,14 +88,14 @@ updateCommand = CommandUI {
   }
 
 upgradeCommand  :: CommandUI (Cabal.ConfigFlags, InstallFlags)
-upgradeCommand = cabalConfigureCommand {
+upgradeCommand = configureCommand {
     commandName         = "upgrade",
     commandSynopsis     = "Upgrades installed packages to the latest available version",
     commandDescription  = Nothing,
     commandUsage        = usagePackages "upgrade",
     commandDefaultFlags = (mempty, defaultInstallFlags),
     commandOptions      = \showOrParseArgs ->
-         liftOptionsFst (commandOptions cabalConfigureCommand showOrParseArgs)
+         liftOptionsFst (commandOptions configureCommand showOrParseArgs)
       ++ liftOptionsSnd [optionDryRun]
   }
 
@@ -203,13 +200,13 @@ defaultInstallFlags = InstallFlags {
   }
 
 installCommand :: CommandUI (Cabal.ConfigFlags, InstallFlags)
-installCommand = cabalConfigureCommand {
+installCommand = configureCommand {
     commandName         = "install",
     commandSynopsis     = "Installs a list of packages.",
     commandUsage        = usagePackages "install",
     commandDefaultFlags = (mempty, defaultInstallFlags),
     commandOptions      = \showOrParseArgs ->
-         liftOptionsFst (commandOptions cabalConfigureCommand showOrParseArgs)
+         liftOptionsFst (commandOptions configureCommand showOrParseArgs)
       ++ liftOptionsSnd 
              (optionDryRun : optionRootCmd :
               case showOrParseArgs of      -- TODO: remove when "cabal install" avoids