be ignored by the SiteErrorLog (thanks to philikon).

       'rest-input-encoding' and 'rest-output-encoding' config file
       directives rather than the REST_INPUT_ENCODING and
       REST_OUTPUT_ENCODING environment variables.

     - Datetime-format settings are now configured via the
       'datetime-format' configuration file directive rather than the
       DATETIME_FORMAT environment variable.

     - Trusted proxies are now configured via the 'trusted-proxy'
       configuration file directive rather than the
       ZOPE_TRUSTED_PROXIES environment variable.

Import TemporaryFolder into zope schema so it can be specified in a config file.

- Deprecate the TemporaryFolder class and ad-hoc mounting machinery
  which surrounds it by removing it from the Add.. list.
  Instead of using this class to provide a ZODB mount point, we now
  use DBTab.

to do so.

DBTab now obtains all values related to storages and databases from zope.conf.  It is also now just a package rather than a product.

A new product named ZODBMountPoint exposes the mount point functionality to the ZMI.

Ensure that ZServer startup messages make it to the logfile and to stdout if we're running in debug mode.

Fix some stale comments.

Do a bit of cleanup in __init__ (add explanatory comments, move side-effect functions to a utility module).

refers to 'if len(step) == 0').

Default to zdrun daemon status "on" (effectively prevents signals from reaching child processes).  This will prevent the symptom of killing the server when pressing ctrl-C from an interactive logtail.

Also ignore child process return statuses.  If we don't, an interactive zopectl shell can clutter up the process table with zombies after a few starts and stops.