New Prolog files for semantic analysis (semantic.pl), symbol table (stable.pl) and known types (types.pl).
Lots of changes in grammar.
fznslurp is now fzsem; new "name" action.
% == No, Emacs this is -*-Prolog-*- code, not what you thought... =============
% sa_type/2 - locate the TYPE field
sa_type(var(_NAME,TYPE,_INIT,_ANNOT), TYPE).
sa_type(constraint(_NAME)).
