Removing deprecated Index
Major refactoring

Incompatible changes to some names.

RingHandlerProvider becomes RingHandler.

Added modules for templates, menus, Netty and MQTT.

Added utility modules for component construction and wiring.

Template variables are scoped by component name.

Components that contribute bidi routes must also export handler
maps. This is to enable URI construction to handlers in foreign
components, using a pair notation [:component :handler-key]