Update to Web API v2 RC
Add a ViewResult implementing IHttpActionResult and remove the no longer needed TaskHelpers.
Make View a sealed, internal class. ViewResult should be used if returning an explicit representation.
Update NuGet
Continue refactoring to more idiomatic Web API 2 IHttpActionResult use.
Clean up namespaces and APIs.
Fix issue in XML doc comments.
Merge branch 'master' into v2-rc

Conflicts:
	.nuget/NuGet.exe
	.nuget/NuGet.targets
	src/WebApiContrib.Formatting.Html/packages.config