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
Fixes specs
Fixes cukes
Adapts identifier methods
Renames 'end date' to 'due date'
Renames further 'end date' references
Removes superfluous locals
Renames permitted param
Add 'end date' migration for timelines options
Adapts cuke
Merge pull request #485 from opf/feature/rails3_fix_planning_element_api

Feature/rails3 fix planning element api