proxied exporttree=yes versionedexport=yes remotes are not untrusted

This removes versionedExport, which was only used by the S3 special
remote. Instead, versionedexport=yes is a common way for remotes to
indicate that they are versioned.

Annex/Import.hs

@@ -44,6 +44,7 @@ import Annex.Transfer
 import Annex.CheckIgnore
 import Annex.CatFile
 import Annex.VectorClock
+import Annex.SpecialRemote.Config
 import Command
 import Backend
 import Types.Key
@@ -194,7 +195,7 @@ recordImportTree remote importtreeconfig imported = do
 			_ -> noop
 		-- When the remote is versioned, it still contains keys
 		-- that are not present in the new tree.
-		unless (Remote.versionedExport (Remote.exportActions remote)) $ do
+		unless (isVersioning (Remote.config remote)) $ do
 			db <- Export.openDb (Remote.uuid remote)
 			forM_ (exportedTreeishes oldexport) $ \oldtree ->
 				Export.runExportDiffUpdater updater db oldtree finaltree

Annex/SpecialRemote/Config.hs

@@ -93,6 +93,9 @@ exportTreeField = Accepted "exporttree"
 
 importTreeField :: RemoteConfigField
 importTreeField = Accepted "importtree"
+			
+versioningField :: RemoteConfigField
+versioningField = Accepted "versioning"
 
 exportTree :: ParsedRemoteConfig -> Bool
 exportTree = fromMaybe False . getRemoteConfigValue exportTreeField
@@ -100,6 +103,9 @@ exportTree = fromMaybe False . getRemoteConfigValue exportTreeField
 importTree :: ParsedRemoteConfig -> Bool
 importTree = fromMaybe False . getRemoteConfigValue importTreeField
 
+isVersioning :: ParsedRemoteConfig -> Bool
+isVersioning = fromMaybe False . getRemoteConfigValue versioningField
+
 annexObjectsField :: RemoteConfigField
 annexObjectsField = Accepted "annexobjects"