Updated to React 0.9.0

- Updated reactHTMLEqual() assert as React.renderComponentToString() now has a synchronous API
- Had to create a version of React 0.9.0 with ExecutionEnvironment.canUseDOM to false so React.renderComponentToString() doesn't throw errors in unit test assertions
- Boolean HTML attributes are no longer given values in React's HTML String output
- Updated vendored versiom of isomorph to 0.2.1