8.x support

This issue relates to progress toward a 8.x release.

Work has started on an 8.x-2.x release, which will substantially be a rewrite of the module (though I'll of course seek to bring in the content of 1.x functions where possible). I'll update progress here.

As of 21 November 2015, there's still heaps to do. At the moment, I have new plugins types for objects types and settings themselves. I also have the beginnings of the sitewide settings form.