Add support to RegionFactoryBean and the corresponding gfe namespace elements for calling Region.close() during teardown of an application context

It'd be great if support could be added to RegionFactory bean to call Region.close() as part of its destroy() method. I would guess it should probably be configurable (in the same way the call to destroyRegion() is today), although I think true would be an appropriate default for close. I'd also be really pleased to see the ability to configure whether or not close() is called when using the gfe namespace, rather than using the RegionFactoryBean directly.

Thanks,
Andy