If you are a
lazy productive developer, you probably are already using nuget to add CRM SDK assemblies to your project. I generally used to add the CRM2013 SDK using the nuget GUI, but recently I had to change this behaviour.
The reason being CRM 2015 SDK is also available in nuget repo, and it uses the same package name that was previously used to CRM2013 SDK. These are the packages, that now show up with a Microsoft Dynamics CRM 2015 prefix, that were previously used for CRM 2013.