I zigged when I should have zagged in my last checkins.  The IITreeSet should remain unadulterated in the TopicIndex results, and the tests should adjust.

1) items added to a topic index PythonFilteredSet could never be removed upon a reindex, even if they no longer evaluated to be true.  This is fixed.
2) Casey informs me that a IITreeSet is better for this application that an IISet.  This should be a transparent change simply by relying on the keys method, which both have, rather than the iterable IISet.

applications to know less about how this is implemented

Added charset and charset_expr attributes. The charset header is inserted only for text/* content types and defaults to "us-ascii". The MIME spec says this header is optional, but Spam Assassin considers its absence a likely indicator of spam.

when we're looking at version data.

The ExtensionClass imports mentions something about an import lock
problem, but provides no details.  The tests seem unaffected, so I'm
guessing this had to do with the old extension class that was a C
extension.

Added cid and cid_expr fields for the Content-ID header. This is needed for embedding images in a HTML message. The programmer is responsible for the actual value of the Content-ID header; it is not autogenerated.

As the earlier comment indicated, this storage does not support
multiple revisions.  The RevisionStorage tests changed to require
revision support, so the tests now fail.  This might be the right
long-term strategy, but it needs a little thought.

BaseStorage._tid.

file path and does for scripts what "start_zope" does for interactive startup.

Use the configure function from within zopectl, replacing some gnarly exec'd code.

Overhaul how the Application object is initialized (replace long function with a somewhat structured recipe).� Include tests for initializer functionality.

Main and temporary databases are no longer configured by default if databases aren't provided in the configuration.  Change zope.conf.in to specify root and temporary databases.

Don't create "default" databases if none exist in config file.  At least one database (the root database) must be specified in zope.conf for Zope to start properly now.

Dont maintain a configuration separate from that of the global config by using a module-scope global.  This causes problems when the global config changes (the
changes are not picked up here).  This is typically an issue when running unit tests.

Add a dummy dbtab attribute on the DefaultConfiguration for machinery that expects this attribute to exist.

Support for ESMTP user+password authorization. Strange, the last commit didn't seems to stick... Trying again.

Dont try to set attributes on cfg in setConfiguration if we're trying to clear the configuration by passing it None.