Add sourceMap option to react-tools transform

Allow tools like grunt-react to include inline source maps in the
generated JavaScript. Browserify can then combine these source maps when
bundling everything together.

Usage:

```
var transform = require('react-tools').transform;
var output = transform(jsxContent, {
  sourceMap: true,
  sourceFilename: 'source.jsx'
});
```

The `output` will have an inline source map comment appended.
Rebased on master
Revert #1536

It's causing issues in product code. Reverting until it can be
investigated further.
Fix 'this' in static methods

binds static methods on the descriptor to the component's actual constructor, so that `foo.constructor.bar()` and `Foo.bar()` run with the same `this`.
Create ReactEventListener

Per our discussion friday, this creates ReactEventListener and renames variables to use the "handle"
nomenclature.
Remove bad perf metric

Remove a bad perf metric. Will investigate later.
Remove unnecessary topLevelTypes indirection

topLevelTypes is a key mirror, so dependency and topLevelType are always the same here.
Merge pull request #1609 from spicyj/tlt-indirect

Remove unnecessary topLevelTypes indirection
Merge pull request #910 from andrewdavey/react-transform-source-map

Add sourceMap option to react-tools transform
Fix tagtree.tv link

Fixes #1697.
Add 'patternUnits' to SVG attributes.
Add 'patternContentUnits' to SVG attributes.