to be consistent with  the behavior of lv6 and lutin  (and work with the
lurette stdin.stdout mode), and so that lurette works with sasa !

Its basename is the basename of the name of the .dot file.

Also provide a =--gen-register= option generates such a registring ml
file. --gen-register also generate a state.ml skeleton file.

The Makefile test/Makefile.inc also suppose that the types of the state
is defined in state.ml

To do that, I've reorganized the code

Test: with ocaml 4.08, it is impossible to load the same function twice.
Hence the need to define p.mli files for graphs with several nodes.

Also, track missing files and the alea-coloring exemples.

- the move_count node was wrong (missing parenthesis)
- the lemma an the theorem only holds for locally central unfait demon

All the get_* functions (that are of no interest for users) are now in
the Register module.

But I bumped into the "value restriction" limitation
https://stackoverflow.com/questions/22507448/the-value-restriction

Indeed, I need to store functions of 'v in some tables (or references),

And tables are necessaryly weakly polymorphic !

https://v1.realworldocaml.org/v1/en/html/imperative-programming-1.html#side-effects-and-weak-polymorphism

Save/restore the PRGS at checkpoints (necessary for internal demons).

Rationale: it was not really necessary (Algo.neighbor contains almost
the same information), and the Topology.neighbor type was alone in its
module, which looked weird.

For some reason, I believed that the source dir containing the main
program need to be named bin for dune to work smoothly. But actually,
it seems to work fine with src, so let's go for it.