Add svg polygon
cloneWithProps()

what if you want to change the props of a child? This is my first attempt which lets you clone a child and transfer some custom props to it.

There is a fundamental issue with refs here. Since the component is cloned the ref will be broken. And since we can clone multiple times, it might not make sense to support repairing refs.
Rework ReactRootIndex generation

This had a higher probability of collision than originally thought (bad math). This makes the strategy injectable and provies a
no-collision version on the client and an unlikely-to-collide version on the server.
adding warning about the lack of support for onScroll on IE8

Adding `console.warn` about the lack of support for `onScroll` event on IE8
Related to this issue on github https://github.com/facebook/react/issues/631
Add display names to controlled components

These show up as Unknown in the DevTools. They also wrap a native component,
so they show up double.
Support ReactTestUtils.mockComponent.
Let components specify tag for ReactTestUtils.mockComponent to use.

If you're writing a test that involves a mocked component that normally
returns a `<li>` tag from its `render` method as the root element, mocking
it with a dummy `<div>` probably won't work, so you'll want to set

  MyListItemComponent.mockTagName = 'li';

The change to the `.mockImplementation` line makes sense because
`ConvenienceConstructor` is more or less synonymous (for these purposes)
with the wrapper that was previously used:

  function() {
    // This `this` used to be `null`, technically, but
    // ConvenienceConstructor doesn't pay attention to `this` anyway.
    return ConvenienceConstructor.apply(this, arguments);
  }
More tests for 77697f26e32e1625397e6cdcb0defe0a746b7230
Support clipboardData in IE

Use the `clipboardData` object available on `window`, if it's not available on the event object. This allows us to support including the `clipboardData` in cut/copy/paste events in IE.
Make sure the mock is cleared in the EventEmitter test