Not saving document properly.

XWIKI-7864: Allow the Hibernate connection URL configuration to use the Environment Permanent Directory property
* Proper implementation using the Restricted Configuration Source

XWIKI-7866 : List XProperties can contain invalid character when displayed in edit mode (select / radio)

XWIKI-7864: Allow the Hibernate connection URL configuration to use the Environment Permanent Directory property
* Quick fix (I'm sending a proposal for the real solution)

Revert "XWIKI-7748 Removed UnexpectedException since it has been moved to commons-store."

This reverts commit b19f436a.

XWIKI-7864: Allow the Hibernate connection URL configuration to use the Environment Permanent Directory property

* Display only the document content diff for now. The entire document diff (meta data, objects, class, attachments, etc.) will be displayed in 4.1 final.
* Added a script service and some classes to help me generate the diff. I've put them *temporarily* in oldcore. The plan is to integrate them in xwiki-commons-diff module that Thomas is creating but we need to discuss on the code first. I didn't spend too much time designing. I was more focused on the feature (be able to display the diff nicely like on GitHub).

XWIKI-7861:  Fix for release failure. Removed usage of maven-dependency-plugin, instead added dependency.

Revert "[misc] Attempting to fix a race condition which is breaking the build/release."

This reverts commit 1b84aff2.

XWIKI-7679: Separate Message Stream input from Activity Stream

XWIKI-7860: "Failed to register resource with name [type=Velocity,domain=Engines,name=default]" error message

- Changed translations since they no longer reflect the current logic.

Improve extensions ids

Improve extensions ids

* Don't hide the entire progress log after resolving a merge conflict.

XWIKI-7748: xwiki-platform-tool-xmldoc-update-plugin needs to be configured to run with the standard environment.

XWIKI-7748: Add a nice test to make an attachment and cause it to flush data to the on-disk cache then read it back.

* Update the EM UI.

Force proper type