Added shutdown handling to Backplane component.
Added shutdown handling to Backplane component.

Implemented by wiring control-signal path through to the splitter component used internally.

Matt

sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia,sparkslabs/kamaelia