+In addition, bupsplit.c, bupsplit.h, and options.py may be
+redistributed according to the separate (BSD-style) license written
+inside those files.
+
+The definition of the relpath function was taken from CPython (tag
+v2.6, file Lib/posixpath.py, hg-commit 95fff5a6a276) and is covered
+under the terms of the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2.