Implement Eraser Registrar Interface

[Joel]

The current interface is rather weird since we have got 4 different manager interfaces.

Erasure methods could be based on an interface: IErasureMethod, IChainedErasureMethod

• The Guid property of all Erasure methods should be static; implement the Guid property as an interface member instead. This allows us to refer to the erasure method by class name instead of by Guid.

[Joel]

(In #22) We need to be able to allow plugins to define new types of tasks before this can be implemented.

[Joel]

IRegistrar interface and IRegisterable interface defined in r1792

[Joel]

Implemented in r1796.

Do this:

[System.Runtime.InteropServices.Guid("guid")]
public class RegisterableClass : IRegisterable
{
    //yadda
    public Guid Guid
    {
        get { return GetType().GUID; }
    }
}

//When querying:
void Function()
{
    Guid guid = typeof(RegisterableClass).GUID;
}

[Joel]

I don't see a need for the erasure method interface, really. Closing this ticket.