move translate_to_integers and ramps_to_function to aux.py

Signed-off-by: Mattias Andrée <maandree@operamail.com>
split ramps_to_function into ramps_to_function and functionise

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add store and restore

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

Signed-off-by: Mattias Andrée <maandree@operamail.com>
fix data types in documentation

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