* tests/atgeneral.m4, tests/atconfig.in, tests/suite.at: Remove.

* m4/atconfig.m4: Remove.
* tests/testsuite.at, tests/atlocal.in, tests/output.at,
* tests/bison: New.
* tests/regression.at, tests/calc.at: Use m4_define, AT_BANNER,
m4_if, m4_patsubst, and m4_regexp.
* tests/calc.at (_AT_CHECK_CALC, _AT_CHECK_CALC_ERROR): Use an
`input' file instead of echo.

tests/bison

@@ -0,0 +1,11 @@
+#! /bin/sh
+# Wrapper around a non installed bison to make it work as an installed one.
+. ./atconfig
+
+# We want to use the files shipped with Bison.
+BISON_SIMPLE=$top_srcdir/src/bison.simple
+export BISON_SIMPLE
+BISON_HAIRY=$top_srcdir/src/bison.hairy
+export BISON_HAIRY
+
+exec $top_builddir/src/bison ${1+"$@"}