Added property Conversion.IsExtensionMethodGroupConversion to determine whether a method group conversion is being performed on an extension method using extension method invocation syntax (eg. Func<int> f = myEnumerable.Single).
NR.Demo: show details for Conversion objects
Merge branch 'extension-method-group-conversion' of github.com:erik-kallen/NRefactory
Rename IsExtensionMethodGroupConversion -> DelegateCapturesFirstArgument.