* bzrlib/tests/__init__.py: (TestCaseWithMemoryTransport._make_test_root): Fixing the problem at the root, if we usr the real path there, we catch 99% of the consequences.
* bzrlib/tests/test_osutils.py: (TestCanonicalRelPath.test_canonical_relpath_simple, TestCanonicalRelPath.test_canonical_relpath_missing_tail): No need to use realpath here anymore.
* bzrlib/tests/script.py: (ScriptRunner.do_rm): OSX and BSD raises a different exception, and windows too even if that will require real testing (but osutils._delete_file_or_dir use the same trick for unlink so it's a pretty safe bet).
* bzrlib/tests/blackbox/test_outside_wt.py: (TestOutsideWT.test_cwd_log, TestOutsideWT.test_diff_outside_tree): Watch for OSX trick.