Fix scrollLeft/scrollTop warning in latest Chrome

Chrome gives the warnings

```
body.scrollLeft is deprecated in strict mode. Please use 'documentElement.scrollLeft' if in strict mode and 'body.scrollLeft' only if in quirks mode.
body.scrollTop is deprecated in strict mode. Please use 'documentElement.scrollTop' if in strict mode and 'body.scrollTop' only if in quirks mode.
```

the first time getUnboundedScrollPosition is invoked. This fixes it. (All modern browsers support `pageYOffset`; IE 8 doesn't but works properly with `document.documentElement.scrollTop` except in quirks mode which React doesn't support.)
Community Round-up #14
Error message for using refs outside of render() is difficult to understand
Adjust params
fix params
Add unit test for transferPropsTo, "key" should never transfer
Fix npm react having wrong version dependency for envify
Make controlled components and bubbling work in IE

Fixes #708.

Test Plan:
In IE9, tested a controlled text input with the event handler on a containing element, as in the fiddle linked in the original issue. Also tested a controlled radio button as the logic there differs within ReactDOMInput. In both cases, I was able to interact with the controls.
Fix a typo in the working-with-the-browser docs
Add invariant to check getInitialState return value. Fixes #397
Allow changing transitionLeave from false to true

Fixes #724.
Merge pull request #722 from wincent/typo-fix-01

Fix a typo in the working-with-the-browser docs
Merge pull request #728 from spicyj/gh-724

Allow changing transitionLeave from false to true
Add SyntheticDragEvent with "dataTransfer" property
Polyfill/normalize autoFocus across all browsers
Added max line length = 80 for jshint
Escape component keys used in reactid
Merge pull request #729 from syranide/dragevent

Add SyntheticDragEvent with "dataTransfer" property
Merge pull request #714 from syranide/escapekey

Escape component keys used in reactid
Merge pull request #700 from syranide/100%autofocus

Patch missing autoFocus-support in older browsers