Share reconcile transaction in batched updates

Should make #1350 better and will also take away any performance hit from #1157.

Test Plan:
grunt test
Adds svg mask and pattern dom components
Added support for itemscope, itemtype, itemprop.
Updated documentation.
Use camelCase and declare MUST_USE_ATTRIBUTE.
Adds svg pattern and mask components
Stylistic changes.
Start Flux video at 10m21s
Preemptively error when required ES5 shim/shams are not available
Merge pull request #1516 from syranide/es5err

Preemptively error when required ES5 shim/shams are not available
Merge pull request #1504 from spicyj/flux-621

Start Flux video at 10m21s
Make perf show all exclusive time, not just render time.

Currently require('ReactDefaultPerf').printExclusive() shows render
time and aggregate componentMount time.

This makes it show exclusive mount time by tracking a stack.
Merge pull request #1358 from spicyj/one-transaction

Share reconcile transaction in batched updates
Merge pull request #1487 from somethingkindawierd/master

Adds svg mask and pattern dom components
Update Simulate docs to reflect reality

cf. #1532, #1445.
Remove filterAttributes.js

This is no longer needed because of https://github.com/facebook/react/commit/089a494a1f0cc1892f1525fd746bac10c5a55175

mutateHTMLNodeWithMarkup.js was the only one using it.
Merge pull request #1537 from chenglou/rm-filter-attrs

Remove filterAttributes.js
Merge pull request #1491 from naturalatlas/itemscope

Added support for itemscope, itemtype, itemprop attributes.
Add hasOwnProperty checks where appropriate

For boolean-like objects, I've added hasOwnProperty checks in addition to the existing truthiness check even though for most of these dicts, we leave out false keys instead of setting them explicitly to false.

In DOMPropertyOperations, we don't need to check hasOwnProperty if the property is in isStandardName because (with the exception of getPossibleStandardName) the dicts on DOMProperty will now be consistently populated with every valid attribute.
Remove references to autoflow

Most references were removed in 6e59561; this should be the last.