Cache launcher icons

src/tint2conf/main.c

@@ -485,6 +485,7 @@ static void edit_current_theme()
 		GtkWidget *prop;
 		prop = create_properties();
 		config_read_file(file);
+		save_icon_cache(icon_theme);
 		gtk_window_present(GTK_WINDOW(prop));
 		g_free(file);
 	}

src/tint2conf/properties.c

@@ -2222,6 +2222,7 @@ void icon_theme_changed()
 
 	load_icons(launcher_apps);
 	load_icons(all_apps);
+	save_icon_cache(icon_theme);
 }
 
 void launcher_icon_theme_changed(GtkWidget *widget, gpointer data)