d: add support for %printer

Currently we display the addresses of the semantic values.  Instead,
print the values.

Add support for YY_USE across languages.

* data/skeletons/c.m4, data/skeletons/d.m4 (b4_use): New.
* data/skeletons/bison.m4 (b4_symbol_actions): Use b4_use to be
portable to D.

Add support for %printer, and use it.

* data/skeletons/d.m4: Instead of duplicating what's already in
c-like.m4, include it.
(b4_symbol_action): New.
Differs from the one in bison.m4 in that it uses yyval/yyloc instead
of *yyvaluep and *yylocationp.

* data/skeletons/lalr1.d (yy_symbol_print): Avoid calls to formatting,
just call write directly.
Use the %printer.
* examples/d/calc/calc.y: Specify a printer.
Enable traces when $YYDEBUG is set.
* tests/calc.at: Fix the use of %printer with D.

data/skeletons/bison.m4

@@ -555,7 +555,7 @@ m4_defn([b4_actions_])[]dnl
         break;
     }dnl
 ],
-[YY_USE (m4_default([$2], [yykind]));])dnl
+[b4_use(m4_default([$2], [yykind]));])dnl
 m4_popdef([b4_actions_])dnl
 ])