P2P protocol version 2, adding SUCCESS-PLUS and ALREADY-HAVE-PLUS

Client side support for SUCCESS-PLUS and ALREADY-HAVE-PLUS
is complete, when a PUT stores to additional repositories
than the expected on, the location log is updated with the
additional UUIDs that contain the content.

Started implementing PUT fanout to multiple remotes for clusters.
It is untested, and I fear fencepost errors in the relative
offset calculations. And it is missing proxying for the protocol
after DATA.

Remote/Helper/P2P.hs

@@ -19,6 +19,7 @@ import Utility.Metered
 import Utility.Tuple
 import Types.NumCopies
 import Annex.Verify
+import Logs.Location
 
 import Control.Concurrent
 
@@ -32,14 +33,19 @@ type ProtoConnRunner c = forall a. P2P.Proto a -> ClosableConnection c -> Annex
 -- the pool when done.
 type WithConn a c = (ClosableConnection c -> Annex (ClosableConnection c, a)) -> Annex a
 
-store :: RemoteGitConfig -> ProtoRunner Bool -> Key -> AssociatedFile -> MeterUpdate -> Annex ()
+store :: RemoteGitConfig -> ProtoRunner (Maybe [UUID]) -> Key -> AssociatedFile -> MeterUpdate -> Annex ()
 store gc runner k af p = do
 	let sizer = KeySizer k (fmap (toRawFilePath . fst3) <$> prepSendAnnex k)
 	let bwlimit = remoteAnnexBwLimitUpload gc <|> remoteAnnexBwLimit gc
 	metered (Just p) sizer bwlimit $ \_ p' ->
 		runner (P2P.put k af p') >>= \case
-			Just True -> return ()
-			Just False -> giveup "Transfer failed"
+			Just (Just fanoutuuids) -> do
+				-- Storing on the remote can cause it
+				-- to be stored on additional UUIDs, 
+				-- so record those.
+				forM_ fanoutuuids $ \u ->
+					logChange k u InfoPresent
+			Just Nothing -> giveup "Transfer failed"
 			Nothing -> remoteUnavail
 
 retrieve :: RemoteGitConfig -> (ProtoRunner (Bool, Verification)) -> Key -> AssociatedFile -> FilePath -> MeterUpdate -> VerifyConfig -> Annex Verification