activate line length rule
Introducing ChallengeResult to call Response.Challenge()
Issue #65 merge RoutingContext and RequestContext

See the relevant PR in aspnet/Routing#60.

This incorporates the breaking changes.
changing to use list instead of stack
fix a build break due to api change
setting line length to 120 to match our guidelines
Cache action descriptor providers and provide a race safe data structure to get the version.
The default implementation has a safe race, and does not allow for action description addition at runtime.

It can be replaced with an implementation that can reload.

Consumers of the new service that do extra caching are now responsible to look at the version and change the implementation.

TODO: Code Comments + A test to verify action descriptors are not regen-d
Add test
Add xml docs
Cleanup usings, and dead test code
CR feedback
Update Url for monitoring test