Up the number of default results from 20 to 40

The data coming in from analytics says 9.4% of people hitting the
announcments index make it through to the second page. This should mean
more of those users get the results they want faster.
Users can create statistical data sets again

The issue was that in the #new action we were checking permission
against the new unsaved instance, which didn't have an organisation set.
As statistical data sets are access limited by default, if there is no
organisation no one is able to access the new object, which means that
the 'new' form cannot be displayed.
Bug: Admin Filter for World location news articles

https://www.pivotaltracker.com/story/show/46629929
Properly fix steps committed in haste

And tidy up features that were relying on old broken behaviour of the step.