(from the changelog)

es6-shim 0.14.0 (20 Jul 2014)

Properly recognize Symbol.iterator when it is present (#277)
Fix Math.clz's improper handling of values that coerce to NaN (#269)
Fix incorrect handling of negative end index on Array#fill (#270)
Removed Object.getOwnPropertyKeys, which shouldn't be anywhere (#267)
Fixed arity of Map and Set constructors, per 2014.04.27 draft spec (rev 24)
Added a full additional suite of ES6 promise tests (thanks to @smikes!) (#265)
Make Number.isInteger a bit more efficient (#266)
Added npm run test-native to expose how broken implementations are without the shim ;-)
Added additional tests

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