add usage of .NET 4.0 and rhadowing of NUnit for alternative Concordion runners
add usage of .NET 4.0 and rhadowing of NUnit for alternative Concordion runners

ShaKaRee/concordion-net,ShaKaRee/concordion-net,ShaKaRee/concordion-net,concordion/concordion-net,concordion/concordion-net,concordion/concordion-net