Allow display to mix formsets
Pass formset along with form when rendering combined formsets
added placeholder styles for select-box

used by .select2-container and .widget-formset-controls
extend select-box placeholder styles
added .widget-formset styling
updated functionality for mixed formsets
updated html for mixed formsets
js/css build
tag-qualify input.date

avoids double bg on p.date container
updated controls to support both formset scenarios

will properly add a formset to either grouped or combined formsets
return None for no formsets
js/css build
Merge branch 'feature/mixed-formsets' into develop
Merge branch 'develop' into feature/1.7