replacing use of concurrent-1.3.4's ConcurrentReaderHashMap with java.util.concurrent.ConcurrentHashMap
replacing use of concurrent-1.3.4's Latch and Mutex with java.util.concurrent equivalents
replacing use of concurrent-1.3.4's Executor and PooledExecutor with java.util.concurrent equivalents
replacing use of concurrent-1.3.4's SynchronousChannel with java.util.concurrent equivalent
replacing use of concurrent-1.3.4's Latch and Mutex with java.util.concurrent equivalents
- adjusting concurrent:concurrent version to 1.3.4-infinity01
- bumping version to 2.6.1-stardust01 (affects all artifacts as parent POM has been changed)