stub in v2 upgrade

Locations.hs

@@ -23,6 +23,7 @@ module Locations (
 	logFile,
 	logFileKey,
 	hashDirMixed,
+	hashDirLower,
 
 	prop_idempotent_fileKey
 ) where

Upgrade.hs

@@ -11,6 +11,7 @@ import Types
 import Version
 import qualified Upgrade.V0
 import qualified Upgrade.V1
+import qualified Upgrade.V2
 
 {- Uses the annex.version git config setting to automate upgrades. -}
 upgrade :: Annex Bool
@@ -19,4 +20,5 @@ upgrade = do
 	case version of
 		"0" -> Upgrade.V0.upgrade
 		"1" -> Upgrade.V1.upgrade
+		"2" -> Upgrade.V2.upgrade
 		_ -> return True

Upgrade/V2.hs

@@ -5,32 +5,22 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-module Upgrade.V1 where
+module Upgrade.V2 where
 
-import System.IO.Error (try)
 import System.Directory
-import Control.Monad.State (liftIO)
-import Control.Monad (filterM, forM_, unless)
-import System.Posix.Files
 import System.FilePath
-import Data.String.Utils
-import System.Posix.Types
-import Data.Maybe
-import Data.Char
 
 import Types.Key
-import Content
 import Types
-import Locations
-import LocationLog
-import qualified Annex
-import qualified AnnexQueue
 import qualified GitRepo as Git
-import Backend
 import Messages
-import Version
 import Utility
-import qualified Command.Init
+import Locations
+
+upgrade :: Annex Bool
+upgrade = do
+	showNote "v2 to v3"
+	error "TODO"
 
 {- Old .gitattributes contents, not needed anymore. -}
 attrLines :: [String]