Fixed the bug where updated dialog appears after welcome

[B] Friends won't prompt that it is updated just after showing the welcome dialog.
Added support to read notifications

[B] Notifications can now be marked as read.
Translation refresh
Added group support

[F] You can now browse groups. It is only an initial support though, you cannot post anything yet.
Added pages support

[F] You can now browse pages. It is only an initial support though.
Unified cover management