tests/sitecustomize.py

keyword: support copy and rename

copy/rename destinations being unversioned and possibly ignored by
the extension should not contain expanded keywords.

Files copied/renamed from an ignored source are not touched.

Add tests covering both of the above cases, plus the corner case of
cp symlink foo; hg cp -A symlink foo (where foo becomes a regular file).

try:
    import coverage
    if hasattr(coverage, 'process_startup'):
        coverage.process_startup()
except ImportError:
    pass