-Added playlist append menu item to channel and playlist fragments.
-Added debouncing to local playlist fragment to allow saving join when list is reordered or item is deleted.
-Extracted hardcoded strings.
- Migrate to fragments
- Fix#487
- Don't show "Open in popup mode" to channel links
- New backstack of videos
- Change the subscribers count to format using `NumberFormat`, for example some locales use `.` others `,`, this handles it automatically (and the old method had a bug for leading zero, e.g. 4.82.125 instead of 4.082.125)
- Add string 'subscribers' for channels with more than 1 subscriber (plural)
- Popup player chooses the default format and resolution based on the new preference (format)
- Fix taskaffinity of the router activities
- Show title before loading, as it is available from the items already loaded