The Accessory class is very complicated and has lots of limitations.

For example, all User Class (user/*.ts) have to extend from it, which prevent us to extend from different EventEmitters (types, like using typed-emitter)

So I decided to re-design this part of the code and try to remove all related codes of the Accessory class.

See:

• Multi-instance [todo] allow Wechaty to be multi-instance #518
• Blog - New Feature: Multi-Instance Support for Wechaty v0.16(WIP)