[Cython] removing ALL those nasty warnings about string constants

[Stefan Behnel]

Robert Bradshaw wrote:
> I'm all for suppressing warnings as long as you are sure they are not  
> real ones, and it doesn't make the code too verbose. I assume it's a  
> lot of changes like
> 
> SomePyCAPI(%s) to SomePyCAPI((char*)%s)
> 
> ?

Then I'd prefer using a macro like

    #define CHARPTR (char*)

so that we can redefine it to nothing in Py3 where it's not needed (if I
understood correctly).

Stefan