Fix unexpanded macros in GLR defines file.

Reported by Csaba Raduly at
<http://lists.gnu.org/archive/html/bug-bison/2008-11/msg00048.html>.
* THANKS (Csaba Raduly): Add.
* data/glr.c: Fix overquoting on b4_prefix for yylval and yylloc.
* tests/calc.at (_AT_DATA_CALC_Y): If %defines is specified, generate
lexer in a separate module that includes the defines file.
(AT_CHECK_CALC): From AT_FULL_COMPILE, request compilation of lexer
source.
* tests/local.at (_AT_BISON_OPTION_PUSHDEFS): Push AT_DEFINES_IF.
Adjust AT_LOC and AT_VAL to use AT_NAME_PREFIX.
(AT_BISON_OPTION_POPDEFS): Pop AT_DEFINES_IF.
(AT_DATA_SOURCE_PROLOGUE): New.
(AT_DATA_GRAMMAR_PROLOGUE): Use AT_DATA_SOURCE_PROLOGUE.
(AT_DATA_SOURCE): New.
(AT_FULL_COMPILE): Extend to support an additional source file.