Hazelcast module must scope vertx-core test-jar to test

Signed-off-by: Julien Viet <julien@julienviet.com>
change to semantics of currentContext()
Eventbus API changes
Fixed merge conflict
reduce Mx for cloudbees
removed TestUtils.buffersEqual
Future completed with null cannot be completed again

Signed-off-by: Julien Viet <julien@julienviet.com>