change copyright comment style for css so it does not mess with erb
adds migration to add planning_element_types instances to types
removes is_in_chlog from types as it was used nowhere
updates changelog
Merge pull request #439 from opf/fix/css_copyright

change copyright comment style for css so it does not mess with erb
Merge pull request #440 from opf/feature/migrate_planning_element_types_data_to_types