Paket does not add all project references for some NuGet packages

Description

When I install the Prius NuGet package Paket only adds one project reference even though the NuGet package defines two references.

You can see from this nuspec file that Prius needs 2 project references to be added Prius.Contracts.dll and Prius.ORM.dll but when I add this NuGet package to my project Paket only adds a reference to Prius.Contracts.dll

Repro steps

1. Start a new console app in Visual Studio 2013
2. Configure Paket and add a reference to the Prius NuGet package.
3. Run paket install
4. Examine the project references and see that Prius.ORM.dll is not referenced
5. If you write code that uses Prius then the application will fail at startup because Prius.ORM.dll is missing from the bin folder.

Expected behavior

Paket should examine the <references> section of the nuspec file and include all of the references listed there.

Actual behavior

Paket only creates a project reference for the first <reference> listed in this case. I did not find any other examples to see if it is always just the first one that is referenced.

Known workarounds

You can manually add the missing reference to the project

Start by reproducing the issue with the Prius NuGet package and trace Paket's handling of the nuspec section. Verify how project references are created when multiple DLLs are listed. Done means both Prius.Contracts.dll and Prius.ORM.dll are added to the project and the application includes Prius.ORM.dll in its bin folder.