[0.85] due date may be empty


git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20654 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] fix fields name - see #4227

git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20655 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] fix dump - see #4227

git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20656 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] add new fields in user form - see #4227

git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20657 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] minro fix


git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20658 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] fix last


git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20659 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] don't use deprecated function - see#4227

git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@20660 35612d4c-9d10-0410-837c-bf9dd1be60d7