dlang: initial changes to run the calc tests on it

* configure.ac (DCFLAGS): Define.
* tests/atlocal.in: Receive it.
* data/skeletons/d.m4 (api.parser.class): Remove spurious YY.
* data/skeletons/lalr1.d (yylex): Return an int instead of a
YYTokenType, so that we can use characters as tokens.
* examples/d/calc.y: Adjust.
* tests/local.at: Initial support for D.
(AT_D_IF, AT_DATA_GRAMMAR(D), AT_YYERROR_DECLARE(d))
(AT_YYERROR_DECLARE_EXTERN(d), AT_YYERROR_DEFINE(d))
(AT_MAIN_DEFINE(d), AT_COMPILE_D, AT_LANG_COMPILE(d), AT_LANG_EXT(d)):
New.
* tests/calc.at: Initial support for D.
* tests/headers.at

data/skeletons/d.m4

@@ -190,7 +190,7 @@ b4_percent_define_default([[stype]], [[YYSemanticType]])])
 # %name-prefix
 m4_define_default([b4_prefix], [[YY]])
 
-b4_percent_define_default([[api.parser.class]], [b4_prefix[]YYParser])])
+b4_percent_define_default([[api.parser.class]], [b4_prefix[]Parser])])
 m4_define([b4_parser_class], [b4_percent_define_get([[api.parser.class]])])
 
 #b4_percent_define_default([[location_type]], [Location])])

data/skeletons/lalr1.d

@@ -69,7 +69,7 @@ public interface Lexer
    * to the next token and prepares to return the semantic value
    * ]b4_locations_if([and beginning/ending positions ])[of the token.
    * @@return the token identifier corresponding to the next token. */
-  YYTokenType yylex ();
+  int yylex ();
 
   /**
    * Entry point for error reporting.  Emits an error