Code re-organisation to abstract Lucky concrete concepts from the
rest of the modules. More precisely, the lucky tools now rely only on Prog (see below), that is Lucky-agnostic. The rationale is to ease the plug of a Lutin programs interpreter afterwards. Indeed, one (ougth to) just need to implement its own version of the Prog module. To do that, I've splitted LusProg into : LucParse LucProg Prog Then, I moved the content of Env_state into LucProg. And all this had some consequences, that cause more code movement.