ints in parallel code

[Paolo Carlini]

Paolo Carlini wrote:
> today was going through the parallel code to do some more or less
> formatting and uglifications fixes, when I noticed something potentially
> much more serious: I'm seeing many plain ints around, also for things
> which look like indexes in data, differences of iterators, things like
> that.
In particular, I wish you could double check the various ints used in
the *multiway* functions, which seem all suspect to me.

Paolo.