Bug 1100349 - Implement StereoPannerNode. r=ehsan,smaug

--HG--
extra : rebase_source : c0d3df3c4ea01001c0800997edbdf441c7287fb8
Bug 1100349 - Tests for the StereoPannerNode. r=ehsan

--HG--
extra : rebase_source : 4944c4626f5e6ab40a95be8bc02b4389572077a7
Bug 1092831 - AnalyserNode should have channelCountMode set to "max" by default. r=ehsan

Spec change: https://github.com/WebAudio/web-audio-api/issues/450

--HG--
extra : rebase_source : f8e71f73e45f31e31c745e29e4b694778d7db445