Replaced CopyOnWriteArrayList with a JsonArray wrapping an ArrayList with a size hint.
As a verticle instance is guaranteed single threaded the overhead of CopyOnWriteArrayList is unnecessary.
This may have contributed to relatively poor performance on multiple query benchmark.

Introduced RouteMatcher.

Removed direct use of Jackson, instead using JsonArray, JsonObject #encode().

Used HttpServerResponse#end(String), explicit setting of content-length now unnecessary.

Inlined DBHandler as anonymous class so can use closure.

Added #setAcceptBacklog to the HttpServer.

Minor refactorings.