README.rst now replaces README.md.
Fix MANIFEST.in

... hat tip to Hynek at
http://hynek.me/articles/sharing-your-labor-of-love-pypi-quick-and-dirty/
rope backend: Fix a test failing on 2.7

Apparently, rope now can find more info on Thread.join, but only
in py 2.7, not 2.6. Ok?
Add requirements.txt