Explore support of classes

[NekR]

Need to support somehow classes aka components for scope captured tags. Here is few options:

• Using decorators

class MyTag {
  constructor() {};

  @jsx_render
  doRender() {} // might be any name, since decorators marks it as a render function
}

• Inheritance

class MyTag extends JSXElement {
  constructor() {
    super();
  }

  render() {} // predefined name dictated by JSXElement
}