Allows this syntax to work now:
@Model.Children.Where("updateDate < DateTime.Now.AddDays(-2)")
This didn't work previously in 4.7beta because updateDate was still boxed as an object and object < DateTime can't be implicitly converted
@Model.Children.Where("bodyText.Contains('ipsum')") still doesn't work because the parser doesn't know how to invoke .Contains on a LambdaExpression (yet)
