Split the .NET 4.0 and .NET 4.5 builds out better

The .NET 4.0 project now references WebApi 4.0
The .NET 4.5 project now references WebApi 4.5
Updated to Net.Http.WebApi.OData 2.2.1

Fixes the problem with the 4.5 build still trying to reference the
System.Net.Http 2.0.0 dll instead of the 4.0.0 version