ReactErrorUtils: In prod, just return the original

This will save a stack frame (nice when in a debugger) and presumably be a bit faster.
Add HAS_POSITIVE_NUMERIC_VALUE to DOMProperty and normalize behavior of null values

Uniformly remove null values, rather than sometimes set/remove, could potentially assign 'null' or 'undefined'
Fix ReactDOMTextarea missing "rows" and "cols" attribute, incorrect "size" property
Add more useful ES6 transforms to jsx-internal.
corrections
NEW `grunt complexity` reporting task
filter out tests from complexity report
fixes test runner for IE8
bump webdriver timeouts

fixes #634
fixes #551
Use depth (not owner) to check for root components

Fixes #557.
Merge pull request #617 from subtleGradient/subtlegradient/complexity-task

NEW `grunt complexity` reporting task
Merge pull request #635 from subtleGradient/subtlegradient/fixes-webdriver-test

fixes webdriver issues
Merge remote-tracking branch 'spicyj/depth-not-owner'
Followup fix for lint
Merge pull request #636 from cpojer/rest-parameters-react

Add more useful ES6 transforms to jsx-internal.
Revert "Don't mutate passed-in props"

This reverts https://github.com/facebook/react/pull/576

This approach mutates the default props for the instance on each update,
which causes incorrect behavior. discussed with @balpert. can look into
cloning but this unbreaks.
Bump version of wd

wd 0.2.2 gives `TypeError: Cannot call method 'jsCondition' of undefined` since #551; 0.2.6 is the latest and works so switch to that.
Merge pull request #592 from spicyj/guard-fn

ReactErrorUtils: In prod, just return the original
first work: __DEV__

fix invariant

Get browserify working

remove dead code elimination step since it is not needed due to minifier

use industry standard NODE_ENV
muffinification