The update to RouteInspector to ignore non AspNet routes doesn't work for WebHosted WebAPIs

As part of #715 I've been looking into getting the routes working for WebAPI, and found my fix (#723) to ignore non AspNet routes doesn't completely fix the issue:

1) WebHosted WebAPI routes get mapped from HttpRoute to HttpWebRoute (which is an internal class, and inheirits from Route). This means the RouteInspector IsAssignableFrom() fix doesn't ignore these routes.

2) The Routes tab doesn't filter out non AspNet routes, so they still appear in the Routes tab.

I've made the following changes:

- Changed the RouteInspector to ignore the type HttpWebRoute.

- Specified in the Routes tab the proxied types for AspNet routes, and ignored anything else.

- Changed the RoutesShould tests to use the RouteInspector, so the Routes get changed into their proxied types.

- Added an extra test to check that proxied Route and RouteBase type routes get shown in the Routes tab.