Fix incorrect handling of download counters when adding a new version of an existing package.
Configure NuGet.Core's PhysicalFileSystem to use Common.Logging
Add some audit logging around push/delete packages and user management.
Override GetPackageFilePath so packages stored in non-standard locations can be located for removal.
Start task to remove package from index before deleting from file system to run in parallel.
Bump version to 2.9.4.