check: new developer-reserved AM_TESTS_SETUP variable For reference, see the discussion at: <http://lists.gnu.org/archive/html/automake-patches/2011-01/msg00213.html> * lib/am/check.am [%?PARALLEL_TESTS%] (am__check_pre): Pass also $(AM_TESTS_SETUP). Comments updated, and some typos fixed. * doc/automake.texi (Simple Tests using parallel-tests): Document AM_TESTS_SETUP. Reorder some of the existing documentation a bit. * tests/parallel-tests-am_tests_setup.test: New test. From a suggestion by Ralf Wildenhues.