minor fixes

- ensure mk_extract performs simplification to distribute over extract and removing extract if the range is the entire bit-vector
- ensure bool_rewriter simplifeis disjunctions when applicable.

src/ast/rewriter/th_rewriter.h

@@ -47,6 +47,7 @@ public:
     expr_ref operator()(expr * n, unsigned num_bindings, expr * const * bindings);
 
     expr_ref mk_app(func_decl* f, unsigned num_args, expr* const* args);
+    expr_ref mk_app(func_decl* f, ptr_vector<expr> const& args) { return mk_app(f, args.size(), args.data()); }
 
     bool reduce_quantifier(quantifier * old_q, 
                            expr * new_body,