Fix assorted confusion between Oid and int32.

In passing, also make some debugging elog's in pgstat.c a bit more
consistently worded.

Back-patch as far as applicable (9.3 or 9.4; none of these mistakes are
really old).

Mark Dilger identified and patched the type violations; the message
rewordings are mine.

src/bin/pg_dump/parallel.c

@@ -821,7 +821,7 @@ lockTableNoWait(ArchiveHandle *AH, TocEntry *te)
 					  "       pg_class.relname "
 					  "  FROM pg_class "
 					"  JOIN pg_namespace on pg_namespace.oid = relnamespace "
-					  " WHERE pg_class.oid = %d", te->catalogId.oid);
+					  " WHERE pg_class.oid = %u", te->catalogId.oid);
 
 	res = PQexec(AH->connection, query->data);