[IronPython] overriding methods from C# classes

[Dino Viehland]

Marcin wrote:
> Curt Hagenlocher wrote:
> > Yes. It's universally true in the CLR that you can't override a function
> > in a derived class unless the function was marked as virtual in the base
> > class. IronPython is no different than C# in this regard.
> 
> One thing that would be *nice* for C# noobs like me would be throwing an
> exception in IPY when a method in a base C# class assembly isn't virtual.
> 
Unfortunately some time you want to do this - C# has "new" as well which 
explicitly lets you do this (otherwise it's only a warning).  If anything I
could see us providing a warning here but we'd need some way to squelch it 
as well.  And it would have an additional cost for constructing classes that
I'm not certain would be worth it.