Release 0.8.0

Version 0.7.0: Python 3.7

Version 0.6.1: Fix rm.py

Version 0.6.0: cmp.py -s; rm.py -rf; PyPy

Version 0.5.0: Add option -r for rm.py

Version 0.4.0: Add script which.py

Version 0.3.2: Convert README to reST

Version 0.3.1: Fix release: build scripts with '/usr/bin/env python'

Version 0.3.0: Release at PyPI

Version 0.2.0: add cmp.py and rm.py; test at Travis and AppVeyor