make redrawers optional

Signed-off-by: Mattias Andrée <maandree@operamail.com>
saver must return whether the save was successful or not

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add todo on additional key combinations

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