remove direct mode support from Annex.Content

No longer used. The only possible user of it would be code in
Upgrade.V5, so I verified that the parts of Annex.Content it used were
not used to manipulate direct mode files.

Command/Info.hs

@@ -527,7 +527,7 @@ cachedPresentData = do
 	case presentData s of
 		Just v -> return v
 		Nothing -> do
-			v <- foldKeys <$> lift (getKeysPresent InRepository)
+			v <- foldKeys <$> lift (listKeys InAnnex)
 			put s { presentData = Just v }
 			return v