provide a docstring.

Add a 'connection-class' key to the database definition which you may use to override the stock ZODB Connection class for a given database via the config file.

     - Collector #893: Mailhost: munge_header has been broken for addresses
       containing the recipients full name

     - Collector #342: Avoiding insertion of a BASE tag for file objects
       with content-type text/html

     - Collector #953: fixed namespace collision with form_title in ZMI

       problems.

- minor cleanup

Put in here for binary packagers to rely upon (it's eventually going to be deleted from the inst directory).

Recursively make subdirectories as specified by dirname.

(This is to support interactive instance creation).

Don't put zconfig script into bindir.