Fixes #3254 - Split logic of configuration of Package Manager and configuration of repositories and merge repository configuration of Rug and Zypper

Fixes #3254 - Split logic of configuration of Package Manager and configuration of repositories and merge repository configuration of Rug and Zypper

See http://www.rudder-project.org/redmine/issues/3253 and http://www.rudder-project.org/redmine/issues/3254

This Pull Request take over https://github.com/Normation/rudder-techniques/pull/140 in order to put the modifications into branch 2.4