Propose rename SpeechRecognitionResult.final to .isFinal

SpeechRecognitionResult includes a "readonly attribute boolean final".
[1]  Unfortunately, "final" is a reserved word in JavaScript. Therefore I
propose renaming it to "isFinal" and changing the IDL to:
  "readonly attribute boolean isFinal".

If there's no disagreement, I'll add this to the errata next week.

Thanks,
Glen Shires

[1] http://dvcs.w3.org/hg/speech-api/raw-file/tip/speechapi.html#dfn-final