aspnet/Routing — pull request #87 by rynowak (2014-07-23 19:06:23+00:00)
Title: Fix for issue 85 - Dictionary types should return null on key not found

This change makes RouteValueDictionary a full IDictionary implementation
instead of a subclass of Dictionary.

Followed the patterns used in the old implementation, namely preserving
the struct-returning behavior of Keys/Values/GetEnumerator.