Fix wrong sorting of remotes when using -J

It was sorting by uuid, rather than cost!

Avoid future bugs of this kind by changing the Ord to primarily compare
by cost, with uuid only used when the cost is the same.

This commit was supported by the NSF-funded DataLad project.

Types/Remote.hs

@@ -146,8 +146,13 @@ instance Show (RemoteA a) where
 instance Eq (RemoteA a) where
 	x == y = uuid x == uuid y
 
+-- Order by cost since that is the important order of remotes
+-- when deciding which to use. But since remotes often have the same cost
+-- and Ord must be total, do a secondary ordering by uuid.
 instance Ord (RemoteA a) where
-	compare = comparing uuid
+	compare a b
+		| cost a == cost b = comparing uuid a b
+		| otherwise = comparing cost a b
 
 instance ToUUID (RemoteA a) where
 	toUUID = uuid