revert to C#5 syntax
revert to C#5 syntax

HermanSchoenfeld/NBitcoin,MetacoSA/NBitcoin,dangershony/NStratis,stratisproject/NStratis,MetacoSA/NBitcoin,thepunctuatedhorizon/BrickCoinAlpha.0.0.1,lontivero/NBitcoin,NicolasDorier/NBitcoin