Default::default() does not support arrays of arbitrary length

[alphaville]

This issue concerns the auto-generated C bindings:

let mut y_array : [f64; {{meta.optimizer_name|upper}}_N1] = Default::default();

This will not work for arrays of arbitrary length (it actually works only for small arrays). We need to change it to

let mut y_array : [f64; {{meta.optimizer_name|upper}}_N1] = 
         [0.0; {{meta.optimizer_name|upper}}_N1];