[processor] configure Disruptor's wait strategy #309
Fixes #309 by merging PR #310. Adds a WaitStrategy configuration option.
Add gs-collections rich collections library as a compile dependency.
Tweaks to ForEach action to use gs-collections for iteration, removed unused CTOR parameter.
Tweaks to event router implementations to get maximum efficiency.
Rewrite CachingRegistry to use the gs-collections rich collections library. Addresses #297 by adding a configuration knob for setting a "consumer not found" handler if no consumers were found for a given notification key.
Merge pull request #313 from reactor/enhancement-consumer-registry

Enhance consumer registry
Ignore a test failure for the time being.
Tweak CachingRegistry to provide a copy for iterators.
Tweak the README to reflect recents tests using JMH benchmarks and the latest changes to CachingRegistry