no sense in demo:ing this

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

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

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

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

Signed-off-by: Mattias Andrée <maandree@operamail.com>
derp + demo interpolation

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