Bug 891952.  Named getters for HTMLCollection should never return anything for "".  r=smaug
Bug 1013316.  Implement GetSupportedNames on HTMLAllCollection.  r=smaug

This also fixes the GetSupportedNames on nsContentList HTMLCollections to follow the spec.
Bug 999456.  Page load events should not be cancelable.  r=smaug
Bug 528456.  Enable :scope support in querySelector and scoped stylesheets by default.  r=dholbert