Change CS Group website URL

CS Group changed its website from https://www.c-s.fr/ to https://www.csgroup.eu/

The following files need to be updated:

./Readme.md: Rugged is licensed by [CS GROUP](https://www.c-s.fr/) under
./src/site/site.xml:    <href>http://www.c-s.fr/</href>
./pom.xml:    <url>http://www.c-s.fr/</url>
./pom.xml:          <bottom><![CDATA[Copyright &copy; ${project.inceptionYear}-{currentYear} <a href="http://www.c-s.fr">CS GROUP</a>. All rights reserved.]]></bottom>
./pom.xml:          <bottom><![CDATA[Copyright &copy; ${project.inceptionYear}-{currentYear} <a href="http://www.c-s.fr">CS GROUP</a>. All rights reserved.]]></bottom>
./NOTICE.txt:CS GROUP (http://www.c-s.fr/)

changed milestone to %3.0

assigned to @gprat

changed the description

changed title from Change CS Group website URL to Change CS Group website URL and mail addresses @c-s.fr

changed title from Change CS Group website URL and mail addresses @c-s.fr to Change CS Group website URL

changed the description

The CS logo needs to be changed also in the file site.xml

mentioned in commit 0e36c658

closed with commit 0e36c658