Add relations dependency object
Merge branch 'dev' of github.com:opf/openproject into dev
Use relation dependency object and inject it
Test relations dependency injection
Extract relation specific add controls
Fix tests
Apply custom extensions only if they exist
Handle WP children in relations tab
Remove superfluous test
Resurrect relation header test
Fix code style
Handle WP parent in relations directive
Set relation directive state only if handler is present
Move method refactoring
Move factories to different namespace refactoring
Merge pull request #1716 from opf/feature/refactor_angular_relations

[Feature] Refactor work package relations implementation