Method GetClassID

src/Squirrel/ShellFile.cs:31–32

can't get this to go if I extend IPersist, so put it here:

(out Guid pClassID)

        {
            // can't get this to go if I extend IPersist, so put it here:
            [PreserveSig]
            void GetClassID(out Guid pClassID);

            //[helpstring("Checks for changes since last file write")]      
            void IsDirty();