* added check for empty scheduler
* removed log, old is 1 not 0
* require running in this thread
* test
* added isDirect to callback
* signature fixed
* added drain
* added allowDirectHandling
* disabled for testing
* Add ExecContextScope object to direct call.
* try alternate initialization of ExecContextScope
* remove ExecContextScope, no help. try _fifoSize as part of direct decision.
* strand management to minimize reuse of same strand per listen socket
* blind attempt to address Jenkins shutdown lock up. may remove quickly.
* add filename and line to existing error log message
* Adjust queueOperation() to stop accepting items once isStopping() becomes true.
* revert previous check-in to MMFilesCollectorThread.cpp
* big reformat
* fixed merge conflicts
* Add CHANGELOG entry.
* enable the ability to push results processing to threads
* have ClusterComm push libcurl response processing to Scheduler threads
* tuning changes from Matthew and Michael
* give new defaults to minimum thread count
* create multiple ClusterCommThreads, each with own Communicator object
* put PR notes in change log
* correct speling
* Also drain V8 queue.
* Add prio V8 to switch in canPostDirectly.
* Accept --server.minimal-threads even if maximal threads is not set.
* Reactivate stopping of threads.
Matthew Von-Maszewski
Frank Celler
jsteemann
Andreas Streichardt