ZConfig schema for Zope, and requires less magic

to strings and thus turned into a Fault object).  Thanks to Sandor Palfy
for the patch.

--skel points to an alternate skeleton directory.

--home allows you to write infiles with an alternate zope home

--lib allows you to write infiles with an alternate software home.

Remove --zeo/-z flags, as custom_zodb.py is no longer the preferred method
of configuring custom storages now that we have DBTab in the core,
and you should be able to create a custom skeleton dir with
the right zope.conf.in that has a zeo client storage set up if you need to.

and having a messageid in i18n:attributes

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.