Add React.batchedUpdates to public API

Fixes #906.
Warn when using hyphenated style property names
Update 09.2-form-input-binding-sugar.md

Add better explanation for 2-way data binding to checkboxes using `checkedLink`. As mentionned here: https://github.com/facebook/react/issues/1930
Update 09.2-form-input-binding-sugar.md -> better checkedLink documentation
Adding a note just below the jQuery inclusion in the tutorial to inform that jQuery is not mandatory.
It's linked with #603
Using the markdown's quote syntax and explaining why use include jQuery
Cancelling Travis build on commits with docs updates only.

Currently recognized patterns:

* any Markdown files (*.md)
* any files in docs or examples directories.

Closes facebook/react#1768.
Simplified and improved test-cases for ReactMultiChildText-test
Merge pull request #1974 from jstoja/jquery-tutorial

jQuery note in tutorial
Merge pull request #1990 from syranide/rmctest

Simplified and improved test-cases for ReactMultiChildText-test
Add createElement alias for createDescriptor
Fire onBeforeUpdate for space on Android

We deliberately skip the event, but Android Chrome
doesn't fire the keypress, so this is wrong.
Merge pull request #2000 from RReverser/stop-travis-on-docs

Cancelling Travis build on commits with docs updates only.
Clarify section introducing `props`
Merge pull request #2016 from samselikoff/patch-1

Clarify section introducing `props`
Clarify section introducing callbacks
Merge pull request #2018 from samselikoff/patch-2

Clarify section introducing callbacks
Close <section> tag in sample markup
Copy edit (fix grammar)
Merge pull request #2021 from adammark/patch-1

Close <section> tag in sample markup