* 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.
* Added checks everywhere for CachedValue::construct.
* Enforce 16MiB limit on keys and 4GiB limit on values.
* Protected members behind function calls in anticipation of format change.
* Shrunk CachedValue struct.
* Fixed alignment of CachedValues.
* Fixed improper comparison.
* Augmented cache API and fixed a potential deadlock scenario.
* The RocksDBEdgeIndex now tries to read up to 10 times form the cache on lock_timeout. Instead of rewriting everything after first attempt