Add X-Content-Type-Options: nosniff support to Firefox

User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5 (.NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5 (.NET CLR 3.5.30729) X-Content-Type-Options: nosniff is introduced by the IE Team to disable MIME-sniffing (http://blogs.msdn.com/ie/archive/2008/09/02/ie8-security-part-vi-beta-2-update.aspx). Firefox should support this to disable MIME-sniffing. Reproducible: Always Steps to Reproduce: 1. Open http://franklin.pacificstorms.org/IE8-Test/authoritativeMIME.php Actual Results: Feed reading view is displayed Expected Results: A XML DOM tree is displayed