Added post moderation buttons in SPV

Changelog.md

app/assets/javascripts/app/views/feedback_view.js

.../app/views/single-post-viewer/single_post_content_view.js

...ts/app/views/single-post-viewer/single_post_moderation.js

app/assets/javascripts/app/views/stream_post_views.js

app/assets/stylesheets/single-post-view.css.scss

...plates/single-post-viewer/single-post-actions_tpl.jst.hbs

...plates/single-post-viewer/single-post-content_tpl.jst.hbs

...tes/single-post-viewer/single-post-moderation_tpl.jst.hbs

config/locales/javascript/javascript.en.yml

features/desktop/single_post_view_moderation.feature

features/step_definitions/single_post_view_steps.rb