Commented Issue: PackageRestorer blocks the UI thread while restoring packages [3464]

1. install 2.7 build from master
2. Create new MVC4 application
3. Delete packages folder
4. Build

Actual:
VS freezes for few minutes/seconds (depending on the machine's capability) and then comes back after packages have been restored

Expected:
User should be able to use VS while packages are getting restored
Comments: Fixed. https://nuget.codeplex.com/SourceControl/changeset/e1d1215cff7fddc083c35db0681db56dc41f82ec