Refactor of Route's GetVirtualPath implementation based on System.Web.Http.Routing code in order to fix a few incompatibilities between our implementation and the one at ms.net
Fixed @grendello's comments regarding styling and a few other gotchas by my side.
Merge pull request #629 from pruiz/syswebrouting-fixes2

[Sys.Web.Routing] Refactor of Route's GetVirtualPath implementation based on System.Web.Http.Routing code in order to fix a few incompatibilities between our implementation and the one at ms.net