* added missing function db._transactions(), and equivalent REST API route
GET /_api/transaction
* updated
* use performRequests
* updated CHANGELOG
* added tests, fixed segfault
* use throwNotRunning
* use read transactions for testing (mmfiles blocks with multiple write
transactions on the same collection)
* 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 virtual attributes for enterprise on Methods.cpp
* Working no access collections
* align a comment
* Documentation and test fix
* fixing community build
* implement transaction handler in c++
* add fake request object
* move general code into extra file
* improve error messages for RestJobHandler
* support cancel operation for async jobs with RestTransactionHandler
* fix integration test and add some optional debugging output
* fix returning of context
* fix error type
* fix code in cluster test
* remove unused variable