Add intersecting route matching, which addresses scenario where the aggregated API versions might not be reported correctly

Author: Chris Martinez

src/Microsoft.AspNet.WebApi.Versioning/Dispatcher/ApiVersionControllerAggregator.cs

@@ -12,6 +12,7 @@
     using System.Web.Http.Controllers;
     using System.Web.Http.Routing;
     using Versioning;
+    using static System.StringComparison;
 
     sealed class ApiVersionControllerAggregator
     {
@@ -100,15 +101,17 @@ IEnumerable<HttpControllerDescriptor> EnumerateDirectRoutes()
             }
 
             var template = subroute.Route.RouteTemplate;
-            var comparer = StringComparer.OrdinalIgnoreCase;
             var controllers = from route in routes
-                              where comparer.Equals( route.RouteTemplate, template )
+                              where RouteTemplatesIntersect( route.RouteTemplate, template )
                               from controller in EnumerateControllersInDataTokens( route.DataTokens )
                               select controller;
 
             return controllers.Distinct();
         }
 
+        static bool RouteTemplatesIntersect( string template1, string template2 ) =>
+            template1.StartsWith( template2, OrdinalIgnoreCase ) || template2.StartsWith( template1, OrdinalIgnoreCase );
+
         static IEnumerable<HttpControllerDescriptor> EnumerateControllersInDataTokens( IDictionary<string, object> dataTokens )
         {
             Contract.Requires( dataTokens != null );