We should be warning if a controlled component becomes uncontrolled, or vice versa.

I thought this was fixed in https://github.com/facebook/react/issues/5821, but apparently it was either not fixed for checkbox components, or maybe I subsequently broke it in https://github.com/facebook/react/pull/7003 (or similar).  Regardless, we should fix it.

Demo of case that should warn: https://jsfiddle.net/s4742gkk/

var div = document.createElement('div');
    div.innerHTML = markup;
    expect(div.firstChild.getAttribute('name')).toBe(null);
  });
  it('should display "foobar" for `defaultValue` of `objToString`', function() {
    var objToString = {
      toString: function() {
        return 'foobar';
      },
    };
    var stub = <input type="text" defaultValue={objToString} />;
    stub = ReactTestUtils.renderIntoDocument(stub);
    var node = ReactDOM.findDOMNode(stub);
    expect(node.value).toBe('foobar');
  });
  it('should display `value` of number 0', function() {
    var stub = <input type="text" value={0} />;
    stub = ReactTestUtils.renderIntoDocument(stub);
    var node = ReactDOM.findDOMNode(stub);
    expect(node.value).toBe('0');
  });
  it('should allow setting `value` to `true`', function() {
    var container = document.createElement('div');
    var stub = <input type="text" value="yolo" onChange={emptyFunction} />;
    var node = ReactDOM.render(stub, container);
    expect(node.value).toBe('yolo');
    stub = ReactDOM.render(
      <input type="text" value={true} onChange={emptyFunction} />,
      container
    );