Web Speech Synthesis test

* [W3C Web Speech API Specification - The SpeechSynthesis Interface](https://dvcs.w3.org/hg/speech-api/raw-file/tip/speechapi.html#tts-section)
* [Test page](http://jsbin.com/OCujUdI/1/).

Side note: currently, AFAIK, only Safari for iOS 7 supports this feature.