made it so add_new_constructor_function_template_callback automatically adds the callback to the const version as well
made it so add_new_constructor_function_template_callback automatically adds the callback to the const version as well

xaxxon/v8toolkit,xaxxon/v8toolkit,xaxxon/v8toolkit,xaxxon/v8-class-wrapper,xaxxon/v8-class-wrapper,xaxxon/v8-class-wrapper