Merge pull request #78 from nperron/ust_3692/int/3733_Add_Rudder_doc_to_rudder-webapp_package_bis

Fixes #3733 - Fix wrong and add missing folder for Rudder documentation
Fixes #3725 - Change output of rudder-reports postinst and rudder-upgrade from rudder-webapp
Refs #3725 - Fix typos in output messages
Refs #3725 - Change messages from postinst and rudder-upgrade script to hide details