Update build dependencies

Nothing crazy here. I think the `grunt-contrib-*` updates were mostly to do the same thing I did for not using the shipped utils. Our biggest change was that `browserify`'s transform takes an option now.

A few extra bytes, but also a pretty nice win for JSXTransformer.

```
   raw     gz Compared to master @ 2562813c63814bcdd52c90c9a36e796f2b33088e
-31880  -8162 build/JSXTransformer.js
     =      = build/react-test.js
    +9    +14 build/react-with-addons.js
   +11     +6 build/react-with-addons.min.js
    +9    +13 build/react.js
   +11     +6 build/react.min.js
```