Coverage for Version.pm.

Coverage for Version.pm.

* lib/Automake/tests/Version.pl (test_version_compare): Also
try Automake::Version::check for the version pairs, taking into
account the special-case naming of code forks.
(@tests): Add more test cases.
(test_bad_versions, @bad_versions): New function, new test cases,
to ensure bad version strings are rejected.
* lib/Automake/tests/Version2.pl: New test.
* lib/Automake/tests/Version3.pl: Likewise.
* lib/Automake/tests/Makefile.am (TESTS): Add tests here ...
(XFAIL_TESTS): ... and here, new.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>