[Checkers] Questions about Javari quals

[Mahmood Ali]

Hi Telmo,

I have two questions about the java qualifiers.

1. Should PolyRead accept a String[] value?  If so, what does it mean  
and can you document it?

2. What does @Unmodifiable mean?  I see no use of it in the checker  
itself.  I've heard that at some point it was for immutable classes,  
but it seems that ReadOnly does that now too.  Should we delete it?

- Mahmood