support many criteria at the same time in owi instrument label?

[redianthus]

also this will be the opportunity to fix the criterion/criteria mistake that probably went in many places :-)

One interesting thing is that running owi instrument label many times is not correct if one wants to get many criteria at the same time! Because then, generated instructions may end up instrumented...

One more thing to consider is the fact that we should probably change the type of the label function to take two integer: one for the label number and one for the criterion it relates to, this is fine currently as we can only have one criterion at the same time...