[HORN] Protect names of stateless nodes with a _fun suffix. This was conflicting with existing names in Z3, ie. "abs".[HORN] Better treatment of stateless nodes collecting semantics Fixes issue #13 on github: https://github.com/coco-team/lustrec/issues/13
Resolved conflict when merging salsa with horn_encoding. The current branch is the most updated.
Refactoring of the horn backend with Reset/Step instead of Init/Step.Teme, please perform a string non regression test wrt the previous version, to make sure we have the same model checking results.