- For older version of Razor the HTML comments will be complained about by TahHelperRewriter
- RazorParserFeatureFlags tests now ensure that AllowHtmlCommentsInTagHelpers is true in 2.1 version and false in older versions
- Added extra test for IsHtmlCommentAhead to make sure Razor code transition is allowed in comment tag
- Moved the unallowed html comment ending to a static array.