[feature request] add NavigatorLanguage.language API

[ghost]

Whilst modifying the browser's response headers to obfuscate the user's language preferences this API is rendering the header obsolete. Hence would appreciate it to be included in WAM.

The NavigatorLanguage.language read-only property returns a string representing the preferred language of the user, usually the language of the browser UI
Returns the browser UI language, not the value of the Accept-Language HTTP header.

[pes10k]

Hmm, this will end up hanging on #67 (or maybe #42). If I can get property blocking working in a consistent manner, then this would happen automatically when blocking the HTML5.1 standard (or, in the #42 approach, adding that feature to be blocked). I'm working on it in the 67-block-properties branch now. :)

[ghost]

If possible I would prefer it being separate from HTML5.1 as it might necessary but would want to escape Language fingerprinting through this API instead. Anyways thanks for your hard/excellent work!

[pes10k]

Gotcha gothca, makes sense. The #42 case would I think realistically be the only way I'd get that into the extension then, since I don't want to go down the road of making more sub-sets of standards. On the upside though, I think #42 would not be too bad to implement (fingers crossed). I'll keep my progress on the issue posted at #42. Thanks again!