* tests/calc.at (_AT_CHECK_CALC_ERROR): Receive as argument the

full stderr, and strip it according to the bison options, instead
of composing the error message from different bits.
This makes it easier to check for several error messages.
Adjust all the invocations.
Add an invocation exercising the error token.
Add an invocation demonstrating a stupid error message.
(_AT_DATA_CALC_Y): Follow the GCS: initial column is 1, not 0.
Adjust the tests.
Error message are for stderr, not stdout.

TODO

@@ -14,10 +14,29 @@ into
 when there are no actions.  This can significantly speed up some
 grammars.
 
-* Huge Grammars
-Currently, not only is Bison unable to handle huge grammars because of
-internal limitations (see test `big triangle').  Push the limit beyond
-253.  Be my guest: fix this!
+* Stupid error messages
+An example shows it easily:
+
+src/bison/tests % ./testsuite -k calc,location,error-verbose -l
+GNU Bison 1.49a test suite test groups:
+
+ NUM: FILENAME:LINE      TEST-GROUP-NAME
+      KEYWORDS
+
+  51: calc.at:440        Calculator --locations --yyerror-verbose
+  52: calc.at:442        Calculator --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
+  54: calc.at:445        Calculator --debug --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
+src/bison/tests % ./testsuite 51 -d
+## --------------------------- ##
+## GNU Bison 1.49a test suite. ##
+## --------------------------- ##
+ 51: calc.at:440       ok
+## ---------------------------- ##
+## All 1 tests were successful. ##
+## ---------------------------- ##
+src/bison/tests % cd ./testsuite.dir/51
+tests/testsuite.dir/51 % echo "()" | ./calc
+1.2-1.3: parse error, unexpected ')', expecting error or "number" or '-' or '('
 
 * read_pipe.c
 This is not portable to DOS for instance.  Implement a more portable