Added support for itemscope, itemtype, itemprop.
Updated documentation.
Use camelCase and declare MUST_USE_ATTRIBUTE.
Stylistic changes.
Update Simulate docs to reflect reality

cf. #1532, #1445.
Remove filterAttributes.js

This is no longer needed because of https://github.com/facebook/react/commit/089a494a1f0cc1892f1525fd746bac10c5a55175

mutateHTMLNodeWithMarkup.js was the only one using it.
Merge pull request #1537 from chenglou/rm-filter-attrs

Remove filterAttributes.js
Merge pull request #1491 from naturalatlas/itemscope

Added support for itemscope, itemtype, itemprop attributes.
Add hasOwnProperty checks where appropriate

For boolean-like objects, I've added hasOwnProperty checks in addition to the existing truthiness check even though for most of these dicts, we leave out false keys instead of setting them explicitly to false.

In DOMPropertyOperations, we don't need to check hasOwnProperty if the property is in isStandardName because (with the exception of getPossibleStandardName) the dicts on DOMProperty will now be consistently populated with every valid attribute.
Remove references to autoflow

Most references were removed in 6e59561; this should be the last.
Update Jasmine link
Merge pull request #1552 from t3chnoboy/master

Update Jasmine link
Tweak getting started wording
Be more specific with createClass, renderComponent

Closes #371.
Mention PropTypes in top-level API

cf. #449
Asynchronously load scripts with JSX transformer.
Merge pull request #1558 from nhunzaker/fix-1530

Fix 1530 - Asynchronously load scripts with JSX transformer
Merge pull request #1189 from spicyj/hasown

Add hasOwnProperty checks where appropriate
Use Object.prototype.hasOwnProperty for doc in IE8

Test Plan: Loaded ballmer-peak example in IE8 without errors and interacted with the text field.
Merge pull request #1564 from spicyj/hop-ie8

Use Object.prototype.hasOwnProperty for doc in IE8