STDOUT/STDERR, and echos the output only on a test failure. This
supports the usage of Test::More or Test::Harness without breaking the
existing test suite behavior.
git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@8535 626c5289-ae23-0410-ae9c-e8d60b6d4f22