Created Unassigned: "Automatic Package Restore" feature not work for projects in solution folders [3640]

In Nuget 2.7 new feature "Automatic Package Restore" not work if csproj file is under solution folder.

Environment: VS2012 Ultimate, NuGet 2.7

Steps to reproduce:

1. Create solution and csproj project (ConsoleApplication1 for example)
2. Add any nuget dependency to csproj project (Install-Package EntityFramework for example).
3. Create solution folder (Solution->Add->New Solution Folder) and drag csproj project to solution folder.
4. Delete "packages" folder to emulate missing of nuget packages.
5. Click "Build" on solution and "packages" folder WILL NOT APPEAR.
6. If you move csproj project from solution foler back to top of solution and click "Build" - background window за restoring packages will appear and "packages" folder also WILL APPEAR.

Probably this is BUG in NuGet 2.7 that finding of packages.config files is not recursive - it should iterate recursively through all solution folders in solution.

I suppose this bug is related to bug
https://nuget.codeplex.com/workitem/3625

But 3625 related to NuGet 2.8, NuGet 2.7 also contain this bug.
Will be nice to have hotfix for this, we just can't use new cool feature "Automatic Package Restore" in our solution, using old msbuild-related package restore.