support get_raw_post/save_raw_post/upload_attach

Signed-off-by: TomWu <phperwuhan@gmail.com>
support remove_attachment

Signed-off-by: TomWu <phperwuhan@gmail.com>
support get_online_users/get_participated_topic/get_unread_topic/search_topic/search_post/mark_all_as_read

Signed-off-by: TomWu <phperwuhan@gmail.com>
support dummy get_subscribed_forum,since WBB 4 does not support subscribe forum

Signed-off-by: TomWu <phperwuhan@gmail.com>
support get_subscribed_topic/subscribe_topic/unsubscribe_topic

Signed-off-by: TomWu <phperwuhan@gmail.com>
support get_inbox_stat

Signed-off-by: TomWu <phperwuhan@gmail.com>