Using WeakMap instead of Map

thanks @spiral2k for the idea

Monkey patches functional components using functional component and not a class

This helps us to patch functional components "less" and prepares us for React Hooks.

Added the option to use "customName"

v2.3.0

version v2.3.0

Fixed for inline render functions

Turns out some libraries use render like this:

render = () => {

This means they don't have render in their class prototype.

This version can handle it just right.

Improved how we detect if a component is functional or class components

based on how react does it:
https://overreacted.io/how-does-react-tell-a-class-from-a-function/

Monkey patch "render" instead of "componentDidUpdate"

In Next.js and we assume in other complicated cases, for some reason, inheritance of Component from another Component that inherits from React, doesn't work. Monkey patching render from the other hand does works.

Tested on a complex next.js project.