v5 for direct mode, with automatic upgrade

This includes storing the current state of the HEAD ref, which git annex
sync is going to need, but does not make sync use it.

Command/Upgrade.hs

@@ -11,6 +11,7 @@ import Common.Annex
 import Command
 import Upgrade
 import Annex.Version
+import Config
 
 def :: [Command]
 def = [dontCheck repoExists $ -- because an old version may not seem to exist
@@ -23,6 +24,9 @@ seek = [withNothing start]
 start :: CommandStart
 start = do
 	showStart "upgrade" "."
-	r <- upgrade
-	setVersion defaultVersion
+	r <- upgrade False
+	ifM isDirect
+		( setVersion directModeVersion
+		, setVersion defaultVersion
+		)
 	next $ next $ return r