Changes

Four main changes:
- Add a Jenkinsfile to define the pipeline of publishing the community
web site.
- Update the pipeline for releasing a build version of Silverpeas to the
declarative syntax.
- Update the pipeline for releasing a build version of the SSO library
for Silverpeas
- Improve the pipeline for releasing a build version of Silverpeas
Mobile.
- Fix some bugs

Fix a bug in the pipelines of web site publishing and of Test Docker
image building

Migrate the pipeline syntax on the build of the WBE library to the
declarative syntax.

Fix a possible bug in the pipelines defined in jackrabbit-jca/Jenkinsfile
and in jcr-access-control/Jenkinsfile.

The pipeline of releasing the Jackrabbit JCA is now in declarative
syntax. We check now the dependency on the build version from which the
release will be done and not in master.

The pipeline of releasing JCR Access Control is now in declarative
syntax.

The pipeline of releasing the Silverpeas projects definition is
now in declarative syntax.

Fix a bug in the pipeline constructing a build version of Silverpeas
Mobile.