Adding in unit test for throw signal event in same transaction caught by boundary event, see https://forums.activiti.org/content/boundary-signal-causes-already-taking-transition (and validates the design design of v6!)

Fixed execution listener export (reported here: https://forums.activiti.org/content/execution-listener-not-getting-exported)

Missing getters/setters in Query & Entity

Missing getters/setters in Query & Entity

Similar action as https://github.com/Activiti/Activiti/commit/ddf9b515550c26bc6f884b91e4563e035497f0c2, now for v6. Way more work (as we used the CollectionsUtil heavily in the new behaviours)

Add missing getters to HistoricActivityInstanceQueryImpl (see https://forums.activiti.org/content/switching-persistence-layer)

factor deletion's exception byte array management and the execution/j…

factor deletion's exception byte array management and the execution/job relationship management out into separate methods.

Add support for populating localization values into the DynamicBpmnService cache from activiti extension elements on deployment of a process definition.

* ProcessInstance
* Execution (Process/SubProcess)
* HistoricProcessInstance

In addition, this change includes an improvement to add fallback support for resolving a localization.

(port of v5 commit https://github.com/Activiti/Activiti/commit/08a1fde0fe4cb3aa111bf0cef3ee902010925263) Introduced four new engine event types: historic process instance created/ended and historic activity created/ended, as an alternative to existing events.
The use case is similar to the default process started/ended and activity started/completed, but used the Historic entities which adds additional data (startUserId, duration, etc.).
Also fixed the historic activity instance creation for subprocess start events (were missing + had incorrect end time).

bug fix for null overwrite of formKey if it exissts

[Scripting] Add 'nashorn.global' object to unstored keys. Also add a method to add new keys at runtime.

Merged BpmnDeployer refactoring. Made classnames and class members consistent with typical Activiti conventions. Renamed ExpandedDeployment to ParsedDeployment and extracted Builder and BuilderFactory into its own classes.

Merge branch 'activiti6-bpmn-deployer-refactoring' of https://github.com/stpm/Activiti into stpm-activiti6-bpmn-deployer-refactoring

Ported https://github.com/Activiti/Activiti/commit/bae3f8feb99a0b2f105f3837fa764b6637e530e8  to v6 + added the custom maybatis mappers from v5

Multi instance refactoring: upgrade scripts for IS_MI_ROOT_. Upped the (internal) version to 6.0.0.1.

Multi instance refactoring: introduced the 'IS_MI_ROOT_' column to indicate an execution is the root of a multi instance. Every multi instance (sequential and parallel, parallel already had it) will now spawn an execution that acts as parent for the whole multi instance. This has two benefits: cleanup becomes way easier and it opens up the possibility to dynamically add new instances to a multi instance (not yet implemented).

Porting 'terminateAll' to v6: cherry pick of https://github.com/Activiti/Activiti/commit/a67374d65b93b22590da9e45e149e5433c35408e

Porting 'terminateAll' to v6: cherry pick of https://github.com/Activiti/Activiti/commit/0727dd10c86cbb50089979289e300c6998a159b2

# By Tijs Rademakers
# Via Tijs Rademakers
* 'activiti6' of https://github.com/Activiti/Activiti:
  #710 PR merge to Activiti 6
  Fix history level checking in test
  Fix Activiti 5 compatibility issue due to wrong Context class
  Added dyanmic bpmn support for sequence flow conditions and scripts