Fixes #4147: Enforce creation of UUID at first install

See 2nd answer here : http://askubuntu.com/questions/101962/script-to-only-execute-during-first-install-of-a-package

Is there a reason why we define CFRUDDER_FIRST_INSTALL if there is a way for each packaging system to determine if it's an upgrade or a first install 

for RPM look at this link (section Deal with upgrade) http://wiki.mandriva.com/en/Development/Howto/RPM

http://www.rudder-project.org/redmine/issues/4147