Battery plugin: Rename Preferences to Power manager

This makes it really obvious what the menu entry does.

Signed-off-by: Eric Koegel <eric.koegel@gmail.com>

panel-plugins/battery/battery-button.c

@@ -678,8 +678,8 @@ battery_button_show_menu (BatteryButton *button)
                            "/xfce4-power-manager/presentation-mode",
                            G_TYPE_BOOLEAN, G_OBJECT(mi), "active");
 
-    /* Preferences option */
-    mi = gtk_menu_item_new_with_mnemonic (_("_Preferences..."));
+    /* Power manager settings */
+    mi = gtk_menu_item_new_with_mnemonic (_("_Power manager..."));
     gtk_widget_show(mi);
     gtk_menu_shell_append(GTK_MENU_SHELL(menu), mi);
     g_signal_connect(G_OBJECT(mi), "activate", G_CALLBACK(xfpm_preferences), NULL);