Merge branch 'refactor-rendering-redacting' into 'master'

app/controllers/projects/issues_controller.rb

app/controllers/projects/merge_requests_controller.rb

app/controllers/projects/notes_controller.rb

app/models/note.rb

app/views/projects/notes/_note.html.haml

config/initializers/metrics.rb

lib/banzai/filter/redactor_filter.rb

lib/banzai/note_renderer.rb

lib/banzai/object_renderer.rb

lib/banzai/pipeline/relative_link_pipeline.rb

lib/banzai/redactor.rb

spec/lib/banzai/note_renderer_spec.rb

spec/lib/banzai/object_renderer_spec.rb

spec/lib/banzai/redactor_spec.rb