Merge 105060 from branch 2.12: Fix HelpSys to work with zope.interface.Interface as it did before the deprecated methods of scarecrow Interface.Interface were removed.

(setuptools is a hard-dependency for Zope 2)

(Now support --version option to choose a
 particular version of zc.buildout)

- Ignore pyd's when they're built in place.
- add sphinx section to buildout and make.bat for Windows user
- de-cruft of tree
- revamp of docs
- rework of Windows service stuff to make zopeservice.py in instances unnecessary
- make zopectl work properly on Windows

Changed startup server tests in Zope2 to use a randomized port number, to allow the nightly buildbot to run the tests at the same time for multiple configurations without the port being already in use.

Easier to axe this file than give such a short list compared with the huge number of people who've since contributed.

I haven't changed Makefile to use this sphinx-build in case is screws with whatever is used on docs.zope.org.

Backport removal of experimental support for configuring the Twisted HTTP server as an alternative to ``ZServer``.

o Added "sane" registration of it during initialization of Five, instead
  of registering it via import side effects.

Clearing frees resources, closing also sends out the end-request event. Clones
of the current request need to be cleared, only the actual current request
needs to be closed. Fixes LP #414757.