add json formatted list of remotes

Wherever a list of remotes is shown, --json now enables a json formatted
list.

Command/Fsck.hs

@@ -131,7 +131,7 @@ checkKeyNumCopies key file numcopies = do
 	let present = length safelocations
 	if present < needed
 		then do
-			ppuuids <- Remote.prettyPrintUUIDs untrustedlocations
+			ppuuids <- Remote.prettyPrintUUIDs "untrusted" untrustedlocations
 			warning $ missingNote (filename file key) present needed ppuuids
 			return False
 		else return True

Command/Whereis.hs

@@ -33,7 +33,7 @@ perform key = do
 	if null uuids
 		then stop
 		else do
-			pp <- prettyPrintUUIDs uuids
+			pp <- prettyPrintUUIDs "whereis" uuids
 			showLongNote pp
 			showOutput
 			next $ return True