pyloxi: include all members in OFClass.members

This preserves ordering, which is important because we can't rely on the offset
field for sorting (it may be -1).

The newly passing show() tests are due to the side effect of removing type
fields from pretty printing.
diff --git a/py_gen/tests/of13.py b/py_gen/tests/of13.py
index 638e61d..ab1b4d6 100644
--- a/py_gen/tests/of13.py
+++ b/py_gen/tests/of13.py
@@ -222,73 +222,7 @@
                 fn()
 
     def test_show(self):
-        expected_failures = [
-            ofp.common.action_id,
-            ofp.common.action_id_bsn_mirror,
-            ofp.common.action_id_bsn_set_tunnel_dst,
-            ofp.common.action_id_copy_ttl_in,
-            ofp.common.action_id_copy_ttl_out,
-            ofp.common.action_id_dec_mpls_ttl,
-            ofp.common.action_id_dec_nw_ttl,
-            ofp.common.action_id_experimenter,
-            ofp.common.action_id_group,
-            ofp.common.action_id_header,
-            ofp.common.action_id_nicira_dec_ttl,
-            ofp.common.action_id_output,
-            ofp.common.action_id_pop_mpls,
-            ofp.common.action_id_pop_pbb,
-            ofp.common.action_id_pop_vlan,
-            ofp.common.action_id_push_mpls,
-            ofp.common.action_id_push_pbb,
-            ofp.common.action_id_push_vlan,
-            ofp.common.action_id_set_field,
-            ofp.common.action_id_set_mpls_ttl,
-            ofp.common.action_id_set_nw_ttl,
-            ofp.common.action_id_set_queue,
-            ofp.common.flow_stats_entry,
-            ofp.common.group_desc_stats_entry,
-            ofp.common.instruction,
-            ofp.common.instruction_apply_actions,
-            ofp.common.instruction_clear_actions,
-            ofp.common.instruction_experimenter,
-            ofp.common.instruction_goto_table,
-            ofp.common.instruction_header,
-            ofp.common.instruction_meter,
-            ofp.common.instruction_write_actions,
-            ofp.common.instruction_write_metadata,
-            ofp.common.match_v3,
-            ofp.common.meter_band,
-            ofp.common.meter_band_drop,
-            ofp.common.meter_band_dscp_remark,
-            ofp.common.meter_band_experimenter,
-            ofp.common.meter_band_header,
-            ofp.common.table_feature_prop,
-            ofp.common.table_feature_prop_apply_actions,
-            ofp.common.table_feature_prop_apply_actions_miss,
-            ofp.common.table_feature_prop_apply_setfield,
-            ofp.common.table_feature_prop_apply_setfield_miss,
-            ofp.common.table_feature_prop_experimenter,
-            ofp.common.table_feature_prop_header,
-            ofp.common.table_feature_prop_instructions,
-            ofp.common.table_feature_prop_instructions_miss,
-            ofp.common.table_feature_prop_match,
-            ofp.common.table_feature_prop_next_tables,
-            ofp.common.table_feature_prop_next_tables_miss,
-            ofp.common.table_feature_prop_wildcards,
-            ofp.common.table_feature_prop_write_actions,
-            ofp.common.table_feature_prop_write_actions_miss,
-            ofp.common.table_feature_prop_write_setfield,
-            ofp.common.table_feature_prop_write_setfield_miss,
-            ofp.message.aggregate_stats_request,
-            ofp.message.flow_add,
-            ofp.message.flow_delete,
-            ofp.message.flow_delete_strict,
-            ofp.message.flow_modify,
-            ofp.message.flow_modify_strict,
-            ofp.message.flow_removed,
-            ofp.message.flow_stats_request,
-            ofp.message.packet_in,
-        ]
+        expected_failures = []
         for klass in self.klasses:
             def fn():
                 obj = klass()