update todo

Signed-off-by: Mattias Andrée <maandree@operamail.com>
update todo

Signed-off-by: Mattias Andrée <maandree@operamail.com>
document

Signed-off-by: Mattias Andrée <maandree@operamail.com>
portability

Signed-off-by: Mattias Andrée <maandree@operamail.com>