Added Channel use of router.hold_channel and router.release_channel - and tests for the overall effect with GC'd name objects
Wires::Hub is now Wires::Launcher

--HG--
rename : lib/wires/base/hub.rb => lib/wires/base/launcher.rb
rename : spec/base/hub_spec.rb => spec/base/launcher_spec.rb
Convert should-style assertions in router_table_spec to expect-style
Convert should-style assertions in channel_spec to expect-style
Introducing Wires::Actor