Fix unscopables test
Fix invalid Symbol.iterator test

The test was using Function() which implies global scope. Since
the test tries to access the local variable b there was a
ReferenceError.

Changed the test to use eval instead.
Merge pull request #202 from arv/iterator

Fix invalid Symbol.iterator test
Merge pull request #201 from arv/unscopables

Fix unscopables test
WebKit now supports Math.sign and multi-d11g

(d11g = destructuring)
Merge pull request #211 from webbedspace/webkit172711

WebKit now supports Math.sign and multi-destructuring
Corrected #201 and #202

I just noticed that pulls #201 and #202 actually edited the HTML file
instead of the data-es6.js file. This fixes that.
Merge pull request #212 from webbedspace/gh-pages

Corrected #201 and #202
Added note to WeakMap and WeakSet results

WeakMap and WeakSet constructor arguments, such as new WeakSet([obj1,
obj2]), are not supported in most browser platforms.
Added a further note to Map and Set results

Additionally, it seems only Firefox supports arguments to the Map() and
Set() constructors.