clean uncomprehensive code


git-svn-id: https://forge.indepnet.net/svn/glpi/trunk@21829 35612d4c-9d10-0410-837c-bf9dd1be60d7
more work on change validation see #1330


git-svn-id: https://forge.indepnet.net/svn/glpi/trunk@21830 35612d4c-9d10-0410-837c-bf9dd1be60d7
more for Ticket cost tags for notifications see #4509


git-svn-id: https://forge.indepnet.net/svn/glpi/trunk@21831 35612d4c-9d10-0410-837c-bf9dd1be60d7