* fix some deadlocks found by evil lock manager (tm)
* fix duplicate lock
* fix indentation
* ensure proper lock dependencies
* fix lock acquisition
* removed useless comment
* do not lock twice
* create either a V8 transaction context or a standalone transaction context, depending on if we are called from within V8 or not
* AQL micro optimizations
* use explicit constructor
* only use V8DealerFeature's ConditionLocker for acquiring a free V8 context
entering and exiting the selected context is then done later on without having to hold the ConditionLocker
* remove some recursive locks
* Disable custom deadlock detection when Thread Sanitizer is enabled
* Changing ifdef's
* grr
* broke gcc
* Using atomic for ApplicationServer::_server
* fix premature unlock
* add some asserts
* honor collection locking in cluster
* yet one more lock fix
* removed assertion
* some more bugfixes
* Fixing assert
(cherry picked from commit 1155df173bfb67303077fbe04ee8d909517bfd21)
* added V8 context lifetime control options `--javascript.v8-contexts-max-invocations` and `--javascript.v8-contexts-max-age`
* make thread scheduling take into account most of the tasks dispatched via the io service
* don't enter a context if another thread is using it
* fix potential issues with other threads that could modify the list of contexts while we're waiting for a used context
Jan Christoph Uhde
Frank Celler
Wilfried Goesgens
Jan
Max Neunhöffer
jsteemann