Download JAR files tagged by cancel with all dependencies

Dryuf Concurrent is enhancement over original Java Concurrent Future design. Apart from providing ListenableFuture functionality, it provides flexibility how to handle cancel() operations, can delay the notifications. It allows various types of notification listeners, distinguishing among successful end, failure and end due to cancel request. Last but not least, it has very low memory footprint and excellent performance, even outperforming JDK Future without listener support.