[dev] Separating Sympa::Message::Template from Sympa::Message.
git-svn-id: https://subversion.renater.fr/sympa/branches/sympa-6.2-branch@12593 05aa8bb8-cd2b-0410-b1d7-8918dfa770ce
git-svn-id: https://subversion.renater.fr/sympa/branches/sympa-6.2-branch@12593 05aa8bb8-cd2b-0410-b1d7-8918dfa770ce