"Switch User" via 'xflock4' i.e. 'light-locker-command --lock'.

From the light-locker and LightDM's greeter perspective,
"Lock Screen" and "Switch User" are the same action type.

Of course, this functionality implies working 'light-locker'.

---
 migrate/migrate-config.c  |  4 ++--
 plugins/actions/actions.c | 17 +++++++++--------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/migrate/migrate-config.c b/migrate/migrate-config.c
index d0d49e7..32fda0e 100644
--- a/migrate/migrate-config.c
+++ b/migrate/migrate-config.c
@@ -99,8 +99,8 @@ migrate_config_action_48_convert (gint action)
     case 7: /* ACTION_HIBERNATE */
       return "+hibernate";
 
-    default: /* ACTION_DISABLED */
-      return "-switch-user"; /* something else */
+    default: /* ACTION_SWITCH_USER */
+      return "+switch-user";
     }
 }
 
diff --git a/plugins/actions/actions.c b/plugins/actions/actions.c
index 8aa38f4..4baa2f0 100644
--- a/plugins/actions/actions.c
+++ b/plugins/actions/actions.c
@@ -147,7 +147,7 @@ static ActionEntry action_entries[] =
     NULL, NULL, NULL, NULL, NULL /* not needed */
   },
   { ACTION_TYPE_LOGOUT,
-    "logout-dialog",
+    "logout",
     N_("Log Out"),
     N_("_Log Out"),
     N_("Are you sure you want to log out?"),
@@ -155,7 +155,7 @@ static ActionEntry action_entries[] =
     "system-log-out"
   },
   { ACTION_TYPE_LOGOUT_DIALOG,
-    "logout",
+    "logout-dialog",
     N_("Log Out..."),
     N_("Log _Out..."),
     NULL, NULL, /* already shows a dialog */
@@ -860,7 +860,7 @@ actions_plugin_actions_allowed (void)
   GError          *error = NULL;
 
   /* check for commands we use */
-  path = g_find_program_in_path ("gdmflexiserver");
+  path = g_find_program_in_path ("xflock4");
   if (path != NULL)
     PANEL_SET_FLAG (allow_mask, ACTION_TYPE_SWITCH_USER);
   g_free (path);
@@ -965,7 +965,7 @@ actions_plugin_action_activate (GtkWidget      *widget,
       break;
 
     case ACTION_TYPE_SWITCH_USER:
-      succeed = g_spawn_command_line_async ("gdmflexiserver", &error);
+      succeed = g_spawn_command_line_async ("xflock4", &error);
       break;
 
     case ACTION_TYPE_LOCK_SCREEN:
@@ -1208,12 +1208,13 @@ actions_plugin_default_array (void)
       "+switch-user",
       "+separator",
       "+suspend",
-      "-hibernate",
-      "-separator",
+      "+hibernate",
+      "+separator",
       "+shutdown",
-      "-restart",
+      "+restart",
       "+separator",
-      "+logout"
+      "+logout",
+      "+logout-dialog"
     };
 
   array = g_ptr_array_sized_new (G_N_ELEMENTS (defaults));
-- 
2.1.0