NuGet.Server 2.11.1

Features:

• NuGet.Server - Update to NuGet 2.11.1 to support newer TFM's NuGet/NuGetGallery#3043

Bugfixes:

• Uploading large packages result in OutOfMemoryException NuGet/NuGetGallery#3042
• NuGet.Server support resolving IPackageAuthenticationService d997741