[css-syntax] typo
[css-syntax] Add 'case sensitive' definition.
[css-variables] Define 'case sensitive'.
[css-font-loading] Allow system fonts to return true in check().
[css-font-loading] Switch FontFaceSet#ready() over to an attribute, per discussion with Domenic about consistency.
[css-font-loading] Add [Exposed] to interfaces so they show up in workers properly.
[css-font-loading] Until Anne adds useful language for rejecting with a FooError, be more explicit.