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

Bit vectors: propagation and simple tests

The propagation for the logic operators' subset of bv is done. Adding two files, no serious change to other files.

See merge request !3

       and document

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

   except for arith which is not yet converted

  And all the other occurences of propagate in the sens of register

  For theory initialization

  - Remove Delayed argument of Variable.fresh

     And:
      - remove Sems
      - remove spurious index

Remove the generic eqtype

And inline it where the constraint on the type (values are fresh)
       is enforced.

See merge request !1

       And inline it where the constraint on the type (values are fresh)
       is enforced.