721530 - Url Rewrite module causes major perf regression if enabled on
server

This performance optimization avoids populating the ServerVariables
collection to determine if Url Rewrite is on for the server/request. Using
ServerVariables is very expensive, and the variables we need aren't
brought into the collection by default.

There's no functional change, this is just an optimization.
Add support for direct routes to the Web API controller and action selectors
Merge branch 'master' of https://git01.codeplex.com/aspnetwebstack