name attribute in planning_element_journal in apiv2 was accidentely written as an xml namespace
be sure to use iso8601 times in api v2
rename 'name' to 'subject' and 'end_date' in 'due_date' in planning_element api to be consistent
changelog entry

[ci skip]
allow updating types for planning_elements again
there is no planning_element_type anymore when creating work_packages in v2