Added functional tests for MVC

This PR is based on the feedback received on a previous similar PR. The current PR addressed the main concerns by:
1) Creating a basic web site for testing purposes under test\WebSites. This website can be normally run on IIS express.
2) Creating a project to hold functional tests on test\Microsoft.AspNet.Mvc.FunctionalTests
3) Added the first functional test to validate view rendering.

Existing issues:
1) @davidfowl Is there might be an easier way to reference projects that are not direct siblings but that are children of a sibling folder? I've temporarily put "test\\WebSites" on global.json but I'd like to avoid that.