title: Is this a bug in ServiceStack / Authentication?
body: <p>Trying to use ServiceStack for authentication, and have it re-direct to a login page as follows:</p>
  
  <pre><code>Plugins.Add(new AuthFeature(
              () =&gt; new CustomUserSession(), //Use your own typed Custom UserSession type
              new IAuthProvider[] {
                  new CredentialsAuthProvider(),              //HTML Form post of UserName/Password credentials
                  new TwitterAuthProvider(appSettings),       //Sign-in with Twitter
                  new FacebookAuthProvider(appSettings),      //Sign-in with Facebook
                  new DigestAuthProvider(appSettings),        //Sign-in with Digest Auth
                  new BasicAuthProvider(),                    //Sign-in with Basic Auth
                  new GoogleOpenIdOAuthProvider(appSettings), //Sign-in with Google OpenId
                  new YahooOpenIdOAuthProvider(appSettings),  //Sign-in with Yahoo OpenId
                  new OpenIdOAuthProvider(appSettings),       //Sign-in with Custom OpenId
              }, "http://www.anyURIhereisignored.com"));
  </code></pre>
  
  <p>However the URI argument in this case "<a href="http://www.anyURIhereisignored.com" rel="nofollow">http://www.anyURIhereisignored.com</a>" is simply ignored.</p>
  
  <p>Looking at the class definition for AuthFeature, I see that the htmlRedirect param is declared as optional with a default value of "~/login", however it appears that it is always using that value and ignoring whatever was passed in. It seems that although the htmlRedirect value gets set initially to the passed URI, somehow internally it is never using that, instead always defaulting to "~/login". Is anyone else experiencing the same issue?</p>