CE upstream: Friday

• both modified: CHANGELOG.md
• both modified: app/assets/javascripts/dispatcher.js
• both modified: app/assets/stylesheets/pages/issuable.scss
• both added: app/controllers/projects/merge_requests/application_controller.rb
• both added: app/controllers/projects/merge_requests/creations_controller.rb
• both modified: app/controllers/projects/merge_requests_controller.rb
• both modified: app/models/ability.rb
• both modified: app/models/user.rb
• both modified: app/policies/base_policy.rb
• both modified: app/policies/group_policy.rb
• both modified: app/policies/project_policy.rb
• both modified: app/policies/project_snippet_policy.rb
• both modified: app/services/projects/update_pages_service.rb
• both modified: app/views/projects/issues/_issue.html.haml
• both modified: app/views/projects/merge_requests/index.html.haml
• both modified: app/views/projects/merge_requests/show.html.haml
• both modified: config/routes/project.rb
• both modified: doc/api/namespaces.md
• both modified: lib/api/entities.rb
• both modified: lib/api/namespaces.rb
• both modified: lib/api/projects.rb
• both modified: spec/policies/group_policy_spec.rb
• both modified: spec/policies/project_policy_spec.rb
• both modified: spec/policies/project_snippet_policy_spec.rb
• both modified: spec/requests/api/namespaces_spec.rb
• both modified: spec/requests/api/projects_spec.rb
• both modified: spec/requests/api/v3/projects_spec.rb