Update README.md
Changed v4 Menu base on v3 Menu's behaviours
Fixed the menu

There's a scenario make the menu be duplicated. (Fixed)
Added unit test(simulator) and fixed some bug

Add more testcase by modifying TestModels
Added IsReadOnly result to the request cache key of RequestCacheableSiteMap and RequestCacheableSiteMapNode, as the result may differ between the builder and the presentation layer.
Merge branch 'master' into v4
Updated README
Update README.md
Fixes #189, logic bug when determining matching node.
Created unit tests for RouteValueDictionary.MatchesRoute method.