U4-8361 301 Url Tracking

Adds the ability to add certain headers to a PublishedContentRequest - these are internal for now until we're sure we want to expose them
Adds response headers to tell browsers not to cache the 301 redirects so people can easily change their mind later

src/Umbraco.Web/UmbracoModule.cs

@@ -323,6 +323,14 @@ namespace Umbraco.Web
             LogHelper.Debug<UmbracoModule>("Response status: Redirect={0}, Is404={1}, StatusCode={2}",
                 () => pcr.IsRedirect ? (pcr.IsRedirectPermanent ? "permanent" : "redirect") : "none",
                 () => pcr.Is404 ? "true" : "false", () => pcr.ResponseStatusCode);
+            
+            response.Cache.SetCacheability(pcr.Cacheability);
+
+            foreach (var cacheExtension in pcr.CacheExtensions)
+                response.Cache.AppendCacheExtension(cacheExtension);
+
+            foreach (var header in pcr.Headers)
+                response.Cache.AppendCacheExtension(string.Format("{0}, {1}", header.Key, header.Value));
 
             if (pcr.IsRedirect)
             {