In order to not keep some and simplify the debug gui

      Egraph.Ro.t is Egraph.rt and  Egraph.t is Egraph.wt

Use more first class function for attaching event. The second part scheduled
keep the Dem.t type.

    - But in order to be really useful in fourier factorization is needed

      perhaps some inefficiency since there are more propagators

 - RealValue: constants
 - Dom_interval: interval domaine
 - Dom_polynome: Polynome, pivot (shostak theory like)

 Modifications made by François Bobot, Stéphane Graham-Lengrand and Guillaume
 Bury. The witan licence has been used for the files not mainly modified by Bobot

  - types need to be renamed in popop_types thanks to ocaml module of
    the same name

[Solver|Arith] Work but with many hacks problems with the daemon are registered not delayed but the effect are. They look at only one place

[Test] add some of altergo tests