[0.84] add new hook for add target

git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.84-bugfixes@23020 35612d4c-9d10-0410-837c-bf9dd1be60d7
bug for count items in notification for a contract - fixed #4966

git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.84-bugfixes@23021 35612d4c-9d10-0410-837c-bf9dd1be60d7