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of its parents is not accessible, to be close to what the Publisher does.

- Revert my previous two checkins, they are rather broke with ZODB 3.3

        http://www.zope.org/Collectors/Zope/1527. The patch
        installs a windows 'control handler'. Ctrl+C/Break etc are
        delivered asynchronously (notwithstanding the GIL) to a new
        thread. This new thread triggers a shutdown, then tricks
        asyncore into breaking out of its 'select' call.

      - The ZEO server now records its PID to a file like the ZEO
        client. Defaults to /var/ZEO.pid, and its
        configurable in /etc/zeo.conf.

- Merge a fix from the five-integration branch, with a test.

- Merge a fix from the five-integration branch, with a test.

- Fixed Shared.DC.ZRDB.{RDB|Results} to behave nicely with the new-style extensionclass
- Added a minimal test

Note that doctest support is not done yet!

        ip-address is unset

      - Use 'del' instead of 'list.remove()' in
        Catalog.delColumn(). There can be only one column with the
        same name, and it could potentially break catalog metadata as
        remove() may remove more than one element from the list if
        they have the same value. Also, we already have the list index
        we are interested in deleting so it doesn't make sense to look
        up the value and call 'list.remove()' on it.