* Add SyntaxContent editors.
* Configure the default SyntaxContent editor in the "Edit Mode Settings" administration section, instead of XDOM editor
* Use the SyntaxContent editors in the edit templates (for page content) and for TextArea properties
* Modify XWiki#getEditorPreference() to return the prefered SyntaxContent editor (instead of XDOM)
* modify templates/editors/xdom*.vm template to support SyntaxContent input
* Make sure the leading white-space is not trimmed when editing in Wiki mode

* Fix javadoc
* Allow XE to overwrite the default WYSIWYG editor (use CKEditor instead, for instance)

* Fix the GWT WYSIWYG editor template.
* Bundle the edit module in the default distribution
* Bundle the edit module implementation in the package created by the pacakger plugin.

* Better doc

* Put back the xwiki.rendering.syntaxes property which is still useful for defining the initial list of active syntaxes

* Added missing deps in the Package Mojo

XWIKI-13400: Hibernate does not send characters in the right encoding to the MySQL database in default Debian setup

* minor improvements

[Misc] Fix broken plugin caused by the upgrade of the Maven Plugin Plugin version in the top-level POM (see XCOMMONS-964: Convert XAR plugin to use Maven Plugin annotations). I've tried to update the plugin without success so far.

XWIKI-13292: Provide a test module to use as dependency for the module manipulating oldcore test tools

[Misc] try to fix stackoverflow erros with Jing Relax NG on CI by upgrading the version of the NU Validator

[misc] Avoid downloading already embedded dependencies when depending on xwiki-platform-tool-jetty-resources

* Remove pergmen

This reverts commit 42820362.

* REL info and asserts changes as per guidance.

* More consistent prefix.