Test fractional hours
Split fractional hours in hours and minutes
Merge pull request #2277 from opf/hotfix/17228_handle_fractional_hours

17228 handle fractional hours
Merge branch 'release/4.0' into dev

Conflicts:
	lib/api/v3/work_packages/work_package_representer.rb
	spec/lib/api/v3/work_packages/work_package_representer_spec.rb