Support C# properties in generated proxies

[tjaskula]

For example a protocol like that:

public interface IEntity1
    {
        ICompletes<Entity1State> DefineWith(string name, int age);

        ICompletes<Entity1State> Current { get; }

        void ChangeName(string name);

        void IncreaseAge();
    }

Will not generate the correct handler for Current property because they are not supported