Enable `errexit' shell flag in all tests cxx*.test. * tests/cxx.test: Add call to `set -e'. Related changes. Bumped copyright years. * tests/cxxansi.test: Likewise. * tests/cxxcpp.test: Likewise. * tests/cxxlibobj.test: Likewise. * tests/cxxlink.test: Likewise. * tests/cxxo.test: Likewise. Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>