How to add custom .net library (DLL) to Reference Manager References?

I tried to use vsix's Extension SDK to add custom reference to "Reference Manager" as described here: http://msdn.microsoft.com/en-us/library/jj127119.aspx. But I can't get my extension SDK reference to show for regular .net 4.5.1 library. 

Process:

1. Create vsix project

2. Create SDKManifest

3. create folder structure and put my DLL there: references/commonconfiguration/neutral/CustomLibrary.dll

4. Build and install vsix

4. Create a .net project "class library". When i try to add references: Project -> References -> right Click -> add Reference -> I don't see my custom extension SDK under Assemblies -> Extensions.

It seems to be working only for Windows Store apps.

How can I add extension to "Assemblies -> Extensions"?

Thanks,

Serg