Global symbol registry is wrong

Symbol("foo") doesn't put the symbol into the global registry. The author probably meant Symbol.for here.
fixed symbol.iterator sample
Merge pull request #162 from muratsu/iterator_fix

Fix symbol.iterator sample
Merge pull request #160 from evilpie/patch-1

Global symbol registry is wrong
Add Firefox 34
Firefox 30 is obsolete
Firefox 34 implemented the global symbol registry
Merge pull request #170 from cpeterso/cpeterso/firefox34

Firefox 34 implemented the global symbol registry
ES6: added spreadable strings check

This checks that strings can be spread in both array literals and
function calls.
ES6: Fix two Traceur test results

In a previous commit I wrongly credited Traceur with supporting these
Annex B features. But, it does not actually provide polyfills for
these, instead falling back to the browser host. (#171)
Added build instruction to README.md
Merge pull request #172 from webbedspace/spreadstrings2

ES6: Added separate spreadable strings check
Merge pull request #174 from webbedspace/readme

Added build instructions to README.md
Merge pull request #173 from webbedspace/traceur_test_fixes

ES6: Fix two Traceur test results
ES6: Merged Opera 15+ with Chrome

Since Opera 15+ and Chrome use the same JS engine, and are lockstep
with releases, it makes sense to combine the two. Fixes #153.
Marked Chrome < 35 obsolete
Updated Chrome 37 results

The latest Canary build seems to support for..of and arrows.
Feature name column is no longer dimmed

When a single feature row is selected, the other columns' names are no
longer dimmed. Fixes #128.
Obsolete browser columns are partially desaturated

New feature: when "show obsolete browsers" is enabled, the additional
columns are drawn using slightly desaturated colours to offset them
from the current browsers.
Merge pull request #176 from webbedspace/css

Some CSS changes