Update status embeds (#4742)

- Use statuses controller for embeds instead of stream entries controller
- Prefer /@:username/:id/embed URL for embeds
- Use /@:username as author_url in OEmbed
- Add follow link to embeds which opens web intent in new window
- Use redis cache in development
- Cache entire embed

config/environments/development.rb

@@ -16,9 +16,10 @@ Rails.application.configure do
   if Rails.root.join('tmp/caching-dev.txt').exist?
     config.action_controller.perform_caching = true
 
-    config.cache_store = :memory_store
+    config.cache_store = :redis_store, ENV['REDIS_URL'], REDIS_CACHE_PARAMS
+
     config.public_file_server.headers = {
-      'Cache-Control' => "public, max-age=#{2.days.seconds.to_i}"
+      'Cache-Control' => "public, max-age=#{2.days.seconds.to_i}",
     }
   else
     config.action_controller.perform_caching = false