[-release] Preparing version 6.2.20

[-release] Preparing Sympa 6.2.19b.2

[-release] Preparing Sympa 6.2.19b.1

[-release] Preparing version 6.2.18

[-release] Preparing version 6.2.17b.2

[-release] Preparing version 6.2.17b.1

As well, contact to authors are changed to sympa-developpers.

[-release]Preparing version 6.2.16

git-svn-id: https://subversion.renater.fr/sympa/branches/sympa-6.2-branch@12839 05aa8bb8-cd2b-0410-b1d7-8918dfa770ce