Changed CachingRegistry to address a performance issue when a Reactor is notified of a key for which there are no Consumers registered. Implemented a partitioned cache based on thread id for better performance at the cost of some increase in memory usage.
Tweaked PartitionedReferencePile to use a thread-local Iterator to make it more efficient.
Add ThreadPartitionedAllocator implementation to have a "thread local" Allocator. Also added a couple useful utility classes for using Strings and Numbers with the Allocator since the allocated object has to be a Recyclable.
Tweaks to respect the useCache property.
Tweak for compilation for target 1.6
Tweak for test.
Merge branch 'refs/heads/master' into reactive-streams