Added async tests to .NET 4.0 test project

Removed unused SimpleObjectList class
Added all async tests to NUnit and NUnitLite tests for 4.0 runtime
Enabled nuget package restore
Added pre-build NuGet package restore to msbuild build script
Trying to tweak nuget configuration file to work on mono
Getting mono to download NuGet packages successfully
Adding Microsoft.Build.dll to the repo to see if Mono likes it now
Resigned that it can't work right now on the build server
Revert "Resigned that it can't work right now on the build server"

This reverts commit 05e525ed5a49b7c44f5292621be021e751b276bc.
Revert "Adding Microsoft.Build.dll to the repo to see if Mono likes it now"

This reverts commit deedd51bb33f1f2a2ce8fce76dc8fe73bdbd0388.
Revert "Getting mono to download NuGet packages successfully"

This reverts commit e6e4f38efc4947ad105c9d735475ccff08d67046.
Revert "Trying to tweak nuget configuration file to work on mono"

This reverts commit 5b19c87792bf6f9e121e2abbae4b112b8e98a926.
Revert "Added pre-build NuGet package restore to msbuild build script"

This reverts commit d4a70dddbedf4b5b91d961d07d6283528f709ac2.
Revert "Enabled nuget package restore"

This reverts commit f05bfca461e70081a679ae3a8865d8182cc11f11.
Committing all packages to the repo. NuGet couldn't be any worse.
Using string name of attribute rather than Type
Added Bcl Async binaries, they were ignored before
Printing name of runtime framework in test harness
Removed unused Linq namespace import
Using PreserveStackTrace method in pre-NET 4.5