RoutingHandler updates

Allow setting the fallbackHandler and invalidMethodHandler so they are easier to customize.  I switched from void to using the builder pattern so it is a little more fluent.

Added the ability to combine multiple different RoutingHandlers into one Routing handler.  I am not sure if this was the best way to approach it.  The goal is to have common modules of routes that get shared across web services (ex. /version /info /metrics) and be able to easily plug them into a new service.  I originally wrote my own wrapper to do this but figured it might be useful.