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
Adds spec
Fixes bug
Adds changelog entry
Corrects standard type query method
Merge pull request #500 from opf/feature/rails3_project_settings_types_tab

[FEATURE] Project settings types tab
the fix now even works for empty projects, spec runs, jenkins likes it, changelog merged.
Configuration: make keys overridable via env vars; flatten hierarchy

This results in a new mail configuration format. The old format can
still be used, but shows a deprecation warning.
This also removes support for two even older mail configuration formats.
Rename Redmine::Configuration to OpenProject::Configuration

This removes the configuration test, the test will later be updated
and re-added as a spec.
Add configuration spec
Document configuration and update configuration.yml.example
Make Configuration spec independent of YAML files, test env vars
Adapts identifier methods
Renames 'end date' to 'due date'