* More unit tests.

* Add unit tests

* Add support for recording/replaying the decisions taken during the execution of an extension job.

* Add support for recording/replaying decisions taken during the execution of an interactive job by firing an event whenever a question is answered/asked.
* Add support for answering the question from a QuestionAskedEvent listener (before it reaches the user).

[Misc] Update Checkstyle version to 6.7 (in order to fix sonar build issue, which seems to be https://github.com/checkstyle/checkstyle/issues/853).

* The replayed actions should appear in the history.

* When an interactive sub-job asks a question, the parent job should update its state accordingly (WAITING) because the user interacts with the parent job. For this, the sub-job status needs to keep a reference to the parent job status (not just a flag that says it is a sub-job, like now).
* Make the ReplayJob a GroupedJob and use the same group path as extension jobs: use 'extension/namespace' if the replay targets a single namespace, and 'extension' if the replay targets multiple namespaces or the global namespace. This way a replay job that targets a single wiki will block the extension jobs on that wiki only.

* Reuse the read() method to deserialize because it supports an XML fragment (e.g. when the list of history records is not wraped in <list>).

[misc] Reuse the DocumentBuilderFactory as much as possible since lookuping it all the time is very expensive

This reverts commit cb30f185.

* more bulletproofing in progress logic

XCOMMONS-806: Calculate and make accessible the time spent in each steps of a job progress
XCOMMONS-807: Add script oriented API to notify about progress