WIP

Added graftTree but it's buggy.

Should use graftTree in Annex.Branch.graftTreeish; it will be faster
than the current implementation there.

Started Annex.Import, but untested and it doesn't yet handle tree
grafting.

Command/Info.hs

@@ -597,7 +597,7 @@ getDirStatInfo o dir = do
 getTreeStatInfo :: InfoOptions -> Git.Ref -> Annex (Maybe StatInfo)
 getTreeStatInfo o r = do
 	fast <- Annex.getState Annex.fast
-	(ls, cleanup) <- inRepo $ LsTree.lsTree r
+	(ls, cleanup) <- inRepo $ LsTree.lsTree LsTree.LsTreeRecursive r
 	(presentdata, referenceddata, repodata) <- go fast ls initial
 	ifM (liftIO cleanup)
 		( return $ Just $