`React.createElement` 是不能渲染一个 ViewModel 实例的，于是便提供了渲染方法来渲染 vm。

即可以 render ViewModel 也可以 render React Component
r -> model, props = {}, ...children
h -> tagOrComp, classNameOrProps, props = undefined, ...content
 

可以渲染 Vm 实例的方法，类似于 `React.createElement`
@name h
@public
@param {VmInstance | ReactComponent | string} model
@param {string | object} [propsOrClassName={}]
@param {object} [props=null]
@param {....ReactElement} [children=[]]
@returns {ReactElement}
@example
h(model, 'class-name', {},
// children
'1', '2'
);
h.div({}, 'inner')
h('div', {}, 'inner')
h('div', 'classname', {}, 'inner')
h(Component, 'classname', {},
h.span()
)
function mixedRenderer(model, propsOrClassName, props, ...children) {
  if (model && typeof model === 'object') {
    if (typeof propsOrClassName === 'string') {
      propsOrClassName = { className: propsOrClassName }
      props = props || {}
      props = { ...props, ...propsOrClassName }
    }
    else {
      children = [props].concat(children)
      props = propsOrClassName
    }
    return r.apply(this, [model, props, ...children])
  }
  return h.apply(this, arguments)
}