From Products.PloneHotfix20160830.

This avoids the `repoze.retry` dependency for WSGIPublisher.

Also drive by fix for ZopePageTemplate.

Add new `ZPublisher.utils.recordMetaData` function to replace the
method previously found on the manager.

Change Testing to use the WSGI publisher for functional and testbrowser
based tests incl. functional doctests. Alternatives are available
in `ZServer.Testing`.

These need special casing in the publisher to be treated as successful
and result in transaction commits. Also prefer `raise Redirect` style
over `REQUEST.RESPONSE.redirect`.

Opened database are now found in `Zope2.opened` next to `Zope2.DB`.
Also stop setting client/instance home variables onto `__builtin__`,
those are available from `App.config.getConfiguration()` as
`instancehome` and `clienthome` attributes.

Based on zopefoundation/five.pt@197e65819013fbfd3a436286737f20ddc4c48813.