omitClose for all void elements

According to http://www.w3.org/TR/html5/syntax.html#void-elements the following elements should not specify end tags:

area, base, br, col, embed, hr, img, input, keygen, link, meta, param, source, track, wbr
[Docs] document optional param for renderComponentToString
Add polygon tag to transform

Fixes #1144.
Remove custom attrs properly when setting to null

I don't think this particular codepath was exercised at all (because all the callers call deleteValueForProperty) but this fixes a bug here nonetheless.
included link to React devtools in tooling-integration. fixes #791
Avoid JSX in ReactCSSTransitionGroup code

Supposedly we want these to be plain JS.
Switched from browserify to pure-cjs bundler.
Optimizations and fix for JSXTransformer build.
Dropped dependency on emulation of Node.js native modules.
Added deamdify step for JSXTransformer build.
Unbreak JSX comment comma fix
Remove unused variable
Merge pull request #1243 from jeffcarp/master

Remove unused variable in ballmer-peak
add chinese translation for 01-why-react.md
fix some translation error
fix some translation error
Merge branch 'master' of github.com:rayqian/react

Conflicts:
	docs/docs/01-why-react.zh-CN.md
Renamed `browserify` tasks/configs to `cjs`, updated pure-cjs to 1.9.0 for better build speed.
CommonJS builder config to Grunt style for easier handling and readability.
Merge pull request #1242 from syranide/jsxcomfix

Unbreak JSX comment comma fix
Remove Shirtstarter as an example application.

We have unexpectedly had to shut Shirtstarter down, so it won't serve as a good React.js example any more unfortunately -- sorry for the documentation churn.
Merge pull request #1246 from ericflo/patch-1

Remove Shirtstarter as an example application.
Normalize whitespace for transformed JSX code