Class waitlist feature implementation

[Yongki]

Hi @vancewong ,

I made new clone, this time with little cosmetic and few bug fixings.

class waitlist v0.1

Here is before cancel,

Here is after cancel,

The process of cancel,

Let me know if you still have questions, or you have found bugs or I misinterpret yours.

I believe you are more knowledeable which cosmetics perform well or which ones making slow to the real app.