* src/output.c (output_gram): Rely on nritems, not the

* src/output.c (output_gram): Rely on nritems, not the
0-sentinel.  See below.
Use -1 as separator, not 0.
* src/bison.simple (yyparse): Subtract 1 to the rule numbers.
Rely on -1 as separator in yyrhs, instead of 0.
* tests/calc.at (AT_CHECK_CALC): Now, the parsers no longer issue
twice `Now at end of input', therefore there are two lines less to
expect.