Enabling attribute routes and RouteCollectionRoute

If you use attribute routing then the SiteMap class will not select the correct RouteData on method FindSiteMapNodeFromMvc. This is because with attribute routing you may get a RouteCollectionRoute when requesting it through GetRouteData(httpContext). This Collection will have route matches on the the MS_DirectRouteMatches value. Then you need to get the correct route data from it this matches. I picked the first one.
This is only two lines of code long and easy to merge. I hope it helps.