react 0.14.6 renderToStaticMarkup for CustomComponent

[barak007]

Hi,
Why does renderToStaticMarkup outputs "className" in the markup for "CustomComponent" (hyphenated tag-names)?

React.renderToStaticMarkup(React.createElement('my-div', {className: 'bobi'}));

//outputs
<my-div className="bobi"></my-div>

//expected 
<my-div class="bobi"></my-div>

[jimfb]

Use the class prop instead of className for custom elements.

Custom elements are allowed to do arbitrary processing of their props, so in order to support the full range of attributes, the only viable option is to pass them directly through. #4933