Run using .NET Framework (and "quirks mode") that project.json is targeting

[jcansdale]

NOTE: When running tests using the 'dotnet test' based runners, run using the exact .NET Framework version and "quirks mode" they were compiled for.

When 'Run Test(s)' or 'Test With > .NET Framework' is used, the test runner should use the framework the target assembly was compiled for. Compiling for net20 should execute using .NET 2.0 and net451 should execute using .NET 4.0 with "quirks mode" set to .NET 4.5.1. The current "quirks mode" can be found using, AppDomain.CurrentDomain.SetupInformation.TargetFrameworkName.