[Checkers] Interaction Between Checkers

[Michael Ernst]

Mahmood-

> I was just thinking of how hard it is to have dependancies between  
> current factories now, and was wondering if we can do anything about it.
> 
> Example:
> Any Interned value should be immutable (in the IGJ sense) too.   
> However, I cannot easily describe this relation in the current  
> framework or checkers.

This is an interesting avenue for future work.  I would say that for now we
should focus on more immediate usability issues.  (For now, users won't be
able to take advantage of cross-checker annotation relationships.)  But
let's add this to the list of interesting problems to take on later.

                    -Mike