The `wagtailimages_tags` library was needlessly loaded on the group edit
page. This causes an error on installations that do not use
`wagtailimages`, or test suites for Wagtail plugins that do not use
images directly.
The translator list now only includes translators specifically identified in the .po files, so that we're not listing dormant Transifex accounts that didn't actually do anything :-)
These tests were mis-specified; calling render methods on a value that has not been provided by the block itself (e.g. returned from to_python) has undefined behaviour. In the case of StructBlock, the values passed to render() must be of type StructValue.
This change makes the fix for test_render_unknown_field in #1793 unnecessary (because the other methods take care of eliminating unknown fields), and so this has been reverted.
We can't use {{ querystring }} any more, as that context var has been removed. We nullify the p (page number) parameter in this link as it doesn't make sense to persist this when navigating up/down the tree.
The correct querystring param to nullify is 'p', not 'page'; failure to set this to none means that e.g. viewing page 2 of a listing then browsing to a child page will wrongly take you to page 2 of the child page's listing.
This is necessary now that we don't pass a 'querystring' context var any more. We set p (the page number param) to None because the tree browser's parent page ID is not preserved in this navigation (it's part of the URL path rather than the querystring), so there's no point preserving the page number.
This ensures that the live database state will be reflected in the page editor, which provides two benefits:
* any changes made directly at the model / database level (e.g. automated data imports) will be visible in the editor
* inline child objects will be associated with their actual database IDs even if this information is missing from the revision record. This ensures that their IDs will be preserved on next publish, rather than the records being deleted and recreated (#1853)
This switches Python back to it's default behaviour. Elasticsearch creates a lot of noise with this warning switched on, hiding warnings that may be important.
