Go through both run_make_tests.pl and test_driver.pl and slightly
modernize the Perl and clean up indentation etc. Fix a number of
warnings in the test scripts detected by running with -w.
* tests/test_driver.pl: Move make error string detection out of the
base test driver.
(run_all_tests): Ensure that we always look for tests in the cwd.
* tests/run_make_tests.pl: Use File::Spec for path manipulations.
Correctly use setlocale() when detecting error strings.
Get configuration from the config-flags.pm file not config.status.
* tests/scripts/features/archives: Use new $cwddir variable.
* tests/scripts/features/reinvoke: Add missing semicolon.
* tests/scripts/features/vpath2: Avoid non-existent variable.
* tests/scripts/functions/foreach: Escape variables.
* tests/scripts/misc/bs-nl: Remove non-existing \v escape sequence.
* tests/scripts/misc/general4: Use handy create_file().
* tests/scripts/options/dash-C: Use Cwd/$cwddir.
* tests/scripts/options/dash-I: Use subst_make_string() and #PWD#.
* tests/scripts/options/symlinks: Use File::Spec.
* tests/scripts/targets/DEFAULT: Use create_file and run_make_test.
* tests/scripts/variables/CURDIR: Use run_make_test.
* tests/scripts/variables/automatic: Remove extraneous "\".
* tests/scripts/vms/library: Remove extra "my" and extraneous "\".
* makeint.h: Change MAP_SPACE to MAP_NEWLINE, and add MAP_PATHSEP
and MAP_SPACE which is now MAP_BLANK|MAP_NEWLINE. Create
NEW_TOKEN(), END_OF_TOKEN(), ISBLANK(), ISSPACE() macros.
* main.c (initialize_stopchar_map): Set MAP_NEWLINE only for
newline characters.
* Convert all uses of isblank() and isspace() to macros.
* Examine all uses of isblank() (doesn't accept newlines) and
change them wherever possible to ISSPACE() (does accept newlines).
* function.c (func_foreach): Strip leading/trailing space.
* variable.c (parse_variable_definition): Clean up.
* tests/scripts/functions/foreach: Test settings and errors.
* tests/scripts/functions/call: Rewrite to new-style.
* tests/scripts/misc/bs-nl: Add many more tests for newlines.
Revert a fix for $? including non-existent files as it shows a bug
in the Linux kernel build. Give them a release to fix this.
Add some changes from Eli Z. for Windows changes.
