remove next and previous functionality from router
remove #next and #previous from posts_controller
remove #next_post_path and #previous_post_path from postpresenter
remove PostViewerNav
remove PostViewerAuthor
remove PostViewer
remove PostViewerInteractions
remove PostViewerFeedback
remove template picker functionality
remove template picker
remove useless specs
remove wallpaper-mood template
remove old styles
bump sidekiq
remove old templates
fix typo in lightbox spec
move everything under post-viewer/ to single-post-viewer/
Merge pull request #4618 from svbergerem/fix-typo-lightbox-spec

fix typo in lightbox spec
Add mention in changelog about statistics route, relating to already closed and merged #4602
Merge pull request #4619 from jaywink/statistics-clarification-changelog

Add mention in changelog about statistics route