Only stop if the transition on this element ended

This way it doesn't end when some random element elsewhere on the page has an ending transition.

It must be noted that this is not a complete fix. If you have multiple transitions on the element, it still ends when the first ends.

I ran into this not working (the transition ends almost immediately, because some unrelated transition ends). This fixes it for me, but I was wondering whether this cornercase was considered, and whether the other cornercase (multiple transitions) was considered.

I think it's very hard to get this correct, and think it might be better to make the timeout explicit, or at least allow to set it explicit, and fall back to this behaviour. But I'm really interested in feedback on this one.
Add React.batchedUpdates to public API

Fixes #906.
Don't escape slash; it's unnecessary

Fixes #1444.

Test Plan: grunt fasttest
Guard against contentEditable with children props
Added event parameter
Make sure it works when we have no css transitions
Apply component and mixins specs deterministically
Fixes #1589.
Update todo example. fixes 'Create' that shouldn't happen

Currently, an `onBlur` creates a new todo on `TodoTextInput`. This makes sense for existing items but not for new items. I.e consider the following: 

1. cursor on new item ("What needs to be done?")
2. click 'x' on the first item. 

This results in two actions being fired: 

1. TODO_CREATE, with an empty string as 'text'
2. TODO_DESTROY

The proposed fix doesn't send a TODO_CREATE if `text.trim() === "")`
Correctly trim strings for css properties

* If a unitless value is passed with a space it'll return `1 px`
Warn when using hyphenated style property names
Add missing markerStart, markerMid, markerEnd SVG attributes
Remove unused properties from ReactMount

(useTouchEvents lives in EventPluginUtils.)

Test Plan: jest
Merge pull request #1741 from spicyj/mount-unused

Remove unused properties from ReactMount
Merge pull request #1642 from ryanseddon/trimCSSValues

Correctly trim strings for css properties
{Blog] Community Round-up #19
Change community roundup 19's React Bootstrap author to @stevoland
Merge pull request #1748 from pieterv/community-roundup-19-fix

Change community roundup 19's React Bootstrap author to @stevoland
Fix typo in blog post
Merge pull request #1738 from cassus/master

Add missing markerStart, markerMid, markerEnd SVG attributes
[react jsx transform] Spread attribute -> Object.assign

Add support for spread attributes. Transforms into an Object.assign just
like jstransform does for spread properties in object literals.

Depends on https://github.com/facebook/esprima/pull/22