* tests/calc.at, tests/output.at, tests/regression.at,

* tests/testsuite.at, tests/torture.at: Rely on Autotest 2.52g:
now the tests are run in private dirs, therefore AC_CLEANUP and
family can be simplified to 0-ary.
* tests/atlocal.in: Now that we run `elsewhere' than in tests/,
use abs. path to find config.h.
* tests/calc.at (AT_CHECK_CALC): Don't try to check the compiler's
stderr, there can be way too much random noise.
Instead pass -Werror to GCC and rely on the exit status.
Reported by Wolfram Wagner.

THANKS

@@ -26,6 +26,7 @@ Richard Stallman        rms@gnu.org
 Robert Anisko           anisko_r@epita.fr
 Shura                   debil_urod@ngs.ru
 Tom Lane                tgl@sss.pgh.pa.us
+Wolfram Wagner          ww@mpi-sb.mpg.de
 Wwp                     subscript@free.fr
 
 Many people are not named here because we lost track of them.  We