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.
[addons] Renamed update() directives to commands
Make EventPluginUtils clear dispatchIDs and dispatchListeners

The other dispatch utils clear these out and I found a bug where they weren't being cleared out.
I'm thinking this should probably be done in the `SyntheticEvent` constructor but at least this way it's consistent. Also, I know no one else uses `executeDispatchesInOrderStopAtTrue` except the `ResponderEventPlugin`.
Batch updates caused by handlers in multiple roots

Fixes #1227.

It seems rare that event handlers in two roots nested in the DOM will update the same component in the same tick, but if that happens, the updates should be batched together.
Make MountReady more reusable, reduce allocations

Test Plan:
grunt test
Add clearer invariants to composite spec mixing
Serve unminified react on docs site. Fixes #1359
Move complementary tools to wiki for easier management.
Ignore children with clashing keys

Fixes #566.
Merge pull request #1365 from akre54/unminified-docs-js

Serve unminified react.js on docs site
Merge pull request #1362 from spicyj/cb-queue

Make MountReady more reusable, reduce allocations
Link to Events from Forms

closes #1372
Warn better for key issues

We weren't warning for key issues at the top level (renderComponent)
level at all. This makes us do that, even if it's not quite perfect.

closes #1351
Make rendering to null work and make it injectable

This allows render to return `null`. Under the hood, this renders a `script` tag.

closes #1127
Normalize view and detail properties
Don't fail if target.ownerDocument is null

See f71dbab.
Let early returns do their thing
Merge pull request #813 from spicyj/e-view-detail

Normalize view and detail properties
Document multiple ways to insert comments in JSX
Update 05-reusable-components.md

`any` also seems to accept primitive values, not only objects. And since we already have `React.PropType.object`, the description was confusing.