Test of disruptor for message passing.

So this is just something to take a look at if it's interesting. I have read up on the [LMAX Disruptor](http://lmax-exchange.github.io/disruptor/), which is supposed to be more performant than the standard blocking queue. However, my tests didn't really yield much difference. Maybe there are test scenarios where the LMAX Disruptor would prove beneficial.

I also updated the project to work with gradle 1.6, and included the gradle wrapper, to make it easier to checkout and build the project without requiring external dependencies. If you want, I can create a cleaner commit of just this part.

Also, the AbstractSyncAsyncDisruptorMessageBus is really just a copy of AbstractSyncAsyncMessageBus with the blocking queue replaced.