Journal editable_by? checks if user is the journal owner.
Added update link to activity representer.
Wired up update comment permission to front end.
Add addComment link to work package representer and wire up template.
Merge branch 'dev' into fix/comments-permissions

Conflicts:
	lib/api/v3/work_packages/work_package_representer.rb
Remove unused paths from path helper and fixed activity service test.
Merge branch 'dev' into fix/comments-permissions

Conflicts:
	lib/api/v3/work_packages/work_package_representer.rb
	spec/lib/api/v3/work_packages/work_package_representer_spec.rb
Fixed activities specs.
grr put back in commented out code.
Removed commented out line.
Merge branch 'dev' into fix/comments-permissions
Merge pull request #1644 from opf/fix/comments-permissions

Fix/comments permissions