generalized Annex.Wanted

this should make it easy to use from inside the assistant, where
everything is an AssociatedFile.

Command/Copy.hs

@@ -31,5 +31,5 @@ start to from file (key, backend) = autoCopies file key (<) $
 		Command.Move.start to from False file (key, backend)
 	where
 		shouldCopy = case to of
-			Nothing -> checkAuto $ shouldGet file key
-			Just r -> checkAuto $ shouldSend r file
+			Nothing -> checkAuto $ wantGet (Just file)
+			Just r -> checkAuto $ wantSend (Remote.uuid r) (Just file)

Command/Drop.hs

@@ -32,7 +32,7 @@ seek = [withField fromOption Remote.byName $ \from ->
 
 start :: Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart
 start from file (key, _) = autoCopiesWith file key (>) $ \numcopies ->
-	stopUnless (checkAuto $ shouldDrop from file) $
+	stopUnless (checkAuto $ wantDrop (Remote.uuid <$> from) (Just file)) $
 		case from of
 			Nothing -> startLocal file numcopies key
 			Just remote -> do

Command/Get.hs

@@ -24,7 +24,7 @@ seek = [withField Command.Move.fromOption Remote.byName $ \from ->
 	withFilesInGit $ whenAnnexed $ start from]
 
 start :: Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart
-start from file (key, _) = stopUnless (checkAuto $ shouldGet file key) $
+start from file (key, _) = stopUnless ((not <$> inAnnex key) <&&> checkAuto (wantGet $ Just file)) $
 	autoCopies file key (<) $
 		case from of
 			Nothing -> go $ perform key file