The pattern-matching construct in the logic is now systematically named
"Tcase" in constructors (Ptree.Tmatch -> Tcase). The one in the
programs (supporting exceptions) is now systematically named "Ematch"
(Expr.Ecase -> Ematch, Dexpr.DEcase -> DEmatch). They are now homogeneous
with the other constructors: Term.Tcase, Dterm.DTcase, Ptree.Ematch,
Mltree.Ematch. Smart constructor Expr.e_case was renamed accordingly.