New marketing copy
Changes based on feedback
typo
less aggro
get rid of composition
ReactTransitions: Don't animate undefined children
Transitions: Handle undefined input to mergeKeySet

Gracefully handle undefined input to mergeKeySet.
Make ReactEventTopLevelCallback-test pass

This module-level mock() seems to have been interfering with other tests (26 specs failing). We don't have any other tests that do a module-level mock() so I'm going to assume it isn't supported in the open-source test runner right now. I changed it so only ReactEventEmitter.handleTopLevel is mocked; doing so made ReactEventEmitter complain that TopLevelCallbackCreator wasn't defined so I switched the ReactMount references to use React directly so that ReactDefaultInjection would kick in properly.

With this, all the tests pass.
Don't mutate passed-in props

Depends on #575; fixes #570.  Now we'll be in trouble if someone tries to share objects between calls to getDefaultProps but that was already true of getInitialState and I haven't heard any complaints there.

This is the same number of allocations as before; we're just copying props in the other direction. (In any case, the copy happens only on mount and there are a couple dozen costlier things we're doing already at that time.)
Add explination of autoBind to DOM Event Listener tip
Merge pull request #577 from stillmotion/master

Add explination of autoBind to DOM Event Listener tip
autoBind -> Autobinding

We don't use the term autoBind anywhere any more.
Merge pull request #578 from spicyj/patch-2

autoBind -> Autobinding
Merge branch 'master' of https://github.com/facebook/react into on-demand-events
order object properties consistently
remove transaction argument from componentWillReceiveProps
Use this.getDOMNode() instead of last argument of componentDidUpdate

Context is adding another argument that shifts all of them by one. Since we can already use this.getDOMNode(), it doesn't really make sense to pass it as an argument to that function.
Fix context in callbacks

callbacks like shouldComponentUpdate, componentDidUpdate, etc. were getting the full, unsanitized context, instead of the one that's been filtered down to only the fields allowed to be visible by contextTypes.
Use this.getDOMNode() instead of last argument of componentDidMount
Add nextContext to componentWillReceiveProps

Add `nextContext` as an argument to `componentWillReceiveProps`. We can figure out what to rename the method to later.