Twisted 9 is in the works, first pre-release is available

Hi all! I've done an initial pre-release of Twisted 9. I've made available a set of tarballs (The one called Twisted-9.0.0pre1.tar.bz2 is the main release) and the release notes.

Please try out this prerelease and tell us about any regressions or other release-related problems you find. If all goes well, we want to hear about that too.