Take advantage of nameof to improve our usage of MemberData across the code base.

Substituted all instances of [MemberData("PropertyName")] for [MemberData(nameof(PropertyName))]
This change enables us to take advantage of IDE features like Navigate to source,
find all references, etc. When using Visual Studio.
Updated to use the new target framework in project.json
Issue #668: Sample should be covered by a basic functional test.
Updated build.cmd
Updating ViewStartUtility to use IFileSystem.TryGetParentPath
Fix the sample to await when writing directly to the output stream in a controller.
[Fixes #731] Add unit tests for ReflectedActionDescriptorProvider

1. Added tests that cover parameters in actions.
2. Added tests that cover building the reflected application model.
3. Added tests that cover attribute routed action constraints and default values.
4. Added tests that cover conventionally routed action constraints and default values.
5. Refactored and cleaned up ReflectedActionDescriptorProvider. All the refactors consist
   of extracting blocks of code to separate methods to better display the flow when building
   the action descriptors.
[Fixes #900] Use [Route(...)] on action methods to specify an attribute route that allows all verbs.

1. Changed attribute usage on RouteAttribute.
2. Added a test on action discovery to ensure that actions with [Route] get discovered as
   attribute routed actions.
3. Added a test on reflected action descriptor provider to ensure that an action with [Route] on
   the controller and [Route] on the action results in an action that allows any Http method.