Don't double-escape style names

Previously we were escaping both in createMarkupForStyles and then in createMarkupForProperty; now we escape only in the latter (otherwise the hypothetical style name `b&ckground` would become `b&amp;amp;ckground`).

Test Plan: grunt fasttest
Add harmony transform support in browser (Fixes GH-1420)

I implemented this by checking for `type="text/jsx;harmony"`, since this
has a bit of a cleaner implementation rather than parsing a JSON object
out of a data attribute. If in the future there are other options to
pass, it would make sense to move to a system like that.

Along with adding support, there is also a new example added that's
the basic-jsx example with Harmony syntax.
Change harmony option to "harmony=true"
Merge upstream changes
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() === "")`
Removes value from rendered attributes of textarea
Don't export (undefined) React in main.js

Previously, this was throwing an error. It was unintentionally (I assume) introduced in fc5bb9c.

Test Plan: jest
[jsx] Make sure we throw when we get XML namespaces

https://github.com/facebook/esprima/commit/aad8a2b798ca80342a744aac2869fc1feb0065dd
replaced XJSIdentifer with XJSNamespacedName for namespaced items, so we
need to adjust here accordingly.
Sync out transform tests
Merge pull request #1724 from spicyj/main-nor

Don't export (undefined) React in main.js
Fix tests broken by undefined `window` references in ReactEventListener.

This test breakage blames to e1c2d02fddb40cb0b246d2c2da97b41b6ba378bc.
Merge pull request #1710 from benjamn/fix-tests-broken-by-undefined-window-references

Fix tests broken by undefined `window` references in ReactEventListener.
Fix ReactEmptyComponent disappearing and throwing in IE8
Merge pull request #1542 from remixz/gh-1420

Add harmony transform support in browser

Fixes #1420. Moved some code around in the merge to account for more
changes in the transform code.

Conflicts:
	vendor/browser-transforms.js
Add support for SVG ellipse elements.

Closes #1675
Add support for patternUnits attribute.

The patternUnits attribute defines how a pattern's coordinate system is
defined (x, y, width, height). This is particularly important when using
repeatable patterns in SVG. This commit adds this attribute to the lists
of known properties.

Closes #1548
Add 'patternContentUnits' to SVG attributes.

Closes #1702
Added missing SVG attributes: fill-opacity, font-family, font-size, opacity, stroke-opacity.

Closes #1557
Merge pull request #1464 from spicyj/style-esc

Don't double-escape style names
Expose React.addons.Perf