Hide unnecessary fields in the admins
Hide unnecessary fields in the admins

* Hide some unnecessary fields from Hearings
* Hide Public and Commenting flags from Sections
  (Section commenting option follows that of hearings.)
* Hide Public and Title fields from images
* Hide Public field from labels

Refs #118

vikoivun/kerrokantasi,City-of-Helsinki/kerrokantasi,stephawe/kerrokantasi,stephawe/kerrokantasi,City-of-Helsinki/kerrokantasi,City-of-Helsinki/kerrokantasi,vikoivun/kerrokantasi,City-of-Helsinki/kerrokantasi,stephawe/kerrokantasi,vikoivun/kerrokantasi