Removed demo (requires code not in Guild)

Demo in here relied on code from another library. Removed for now.
Added bridging to Splitter

Bridging allows you to combine Splitters together to join mutiple domains
together easily. The trick is to NOT reuse the publish/subscribe, but to
add in distinct bridge publish/subscribe functions. Then all non-splitters
connect to the publish/subscribe, and splitters connect to the bridging
functions. Thus "publish" goes to all subscribers and bridge subscribers,
allowing messages to traverse, whereas messages from publish_subscribe
only go to subscribers. Bridges are linked by binding a subscribe_bridge
to a publish_bridge.