* 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.
* untested connection count management code.
* add digit to identify location of identical error messages.
* unit tests created, code working and integrated
* subtle changes to smoothing algorithm, close ... but still not perfect
* use scheduler queue() instead of post() to avoid occassional extreme latencies. throughput improved!
* temporary hack to hardcode queue size much lower
* force direct calls to post() to instead route through queue()
* correct issue with previous check-in, but performance has dropped with this on
* revert hardcoded value in SchedulerFeature.cpp
* queue to high priority to be consistent with other Aql actions
* backout all edits to Scheduler.cpp and Scheduler.h
* oops, forgot to remove some testing code.
* 3.4 merge/update
* add changelog entry
* do not use V8 variant of AQL functions in early optimization stage when a C++ variant is available
* additionally, simplify AQL function definitions and aliases
* warn when more than 90% of max mappings are in use
* added C++ variant of replication catchup
* added `--log.role` option
* updated CHANGELOG
* removed non-existing scheduler.threads option from config
* removed useless __FILE__, __LINE__ invocations
* updated CHANGELOG
* allow a priority V8 context
* remove TRI_CORE_MEM_ZONE
* try to fix Windows errors & warnings
* cleanup
* removed memory zones altogether
* exclude system collections from collection tests
- this sets option CURLOPT_PATH_AS_IS to keep ".." and other special components in paths
- this also changes the behavior of StringUtils::urlEncode() to always encode the "."
character to "%2e"