Please excuse me for the delayed reply.
I took us some time to package your required assembly, but now you can find the missing assembly inside the Telerik.DataAccess.Ria.Extensions
NuGet package (version 2015.2.624.1).
We will add that package for all future releases of Telerik Data Access so you will have clear and easy upgrade path.
If you are experiencing any difficulties with this new package or you need further assistance do not hesitate to contact us.
Check out the latest announcement
about Telerik Data Access vNext as a powerful framework
able to solve core development problems.