enable flash message helper to be used in views properly
unify projects type rendering and behavior
disable standard types' checkboxes when it's the last one standing
Adds missing error handling spec
Adds notes spec
Adds journal note on planning element update
Adds routing spec
Adds work package priorities route
Adds view spec
Adds view
Adds controller spec
Implements work package priorities controller
Adds changelog entry
Merge pull request #854 from opf/feature/unified_none_type
Merge remote-tracking branch 'origin/dev' into feature/api_expose_work_package_priorities_3347
Merge pull request #857 from opf/feature/api_expose_work_package_priorities_3347

[FEATURE] API expose work package priorities 3347
Merge pull request #855 from opf/fix/api_planning_elements_update_do_not_accept_journal_notes_3774

[FIX] API planning elements update do not accept journal notes 3774
Update CHANGELOG.md

Updated changelog after PR merge