autoimporttest: add sys to extension_modules for testing

README.txt: update new features section

done.txt: updated for 0.8.4 release

contributing.txt: fixed a typo

done.txt: added changes since last release

project: handling / as project root

docs: documenting new features

docs: updated docs for the new release

docs: updated rope.txt

pycore: fixed importing a name from the same module