such as in the equation
 o1,o2 = current (n(x,y,z));

(It would have avoided issue #8)

close #8

Remove a lot of warnings (considered as errors by dune).

cd rdbg #sha 4a54c7a1181e1200670f3eaf14af1be32823cd04

Indeed the API of Format.formatter_out_functions changed in 4.06.0

To turn around this problem, I've used pp_get_formatter_out_functions
and extend it result

Rationale: a step to make time traveling work correctly.