ISPN-2042 Add easy trace logging facility to the test suite
ISPN-4745 Cluster Listener TX Batch incorrect when sending multiple
events

* Fixed typo where the events were sent inside the for loop
ISPN-3938 AdvancedAsyncCacheLoader.process() concurrency issues

Simplify ExecutorAllCompletionService to track the tasks itself instead of
using an ExecutorCompletionService.