Fieldset fix

This is ready to merge if you need the fix for fieldsets immediately. [Travis does show the build failing](https://travis-ci.org/gboone/cms-toolkit/jobs/33598953) because of changes made to the validation and save routines in ad08e98 but the code should work. I plan to fix the tests this afternoon and will issue another PR with those tests fixed (and readmes re-updated) if this one is merged before I get to it.